Tactile sense presentation device, electronic apparatus, and tactile sense presentation method

ABSTRACT

The tactile sense presentation device, capable of effectively presenting a tactile sense (a sense of texture) on a touch panel, includes: a supporting substrate; a plurality of X-electrodes and Y-electrodes extended in parallel to each other on the supporting substrate; and driving circuits (X-electrode driving circuit, Y-electrode driving circuit) which apply a first-frequency voltage signal to the X-electrode corresponding to information regarding a target region inputted from outside among the plurality of X-electrodes, and applies a second-frequency voltage signal to the Y-electrode corresponding to information regarding the target region inputted from outside among the plurality of Y-electrodes to generate electric beat oscillation in the target region by an absolute value of a difference between the first and second frequencies.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based upon and claims the benefit of priority fromJapanese patent application No. 2013-213009, filed on Oct. 10, 2014 andJapanese patent application No. 2014-153540, filed on Jul. 29, 2014, thedisclosure of which is incorporated herein in its entirety by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a tactile sense presentation device, anelectronic apparatus, and a tactile sense presentation method. Morespecifically, the present invention relates to a tactile sensepresentation device and the like which make it possible to executeoperations only with a tactile sense without looking at the hands.

2. Description of the Related Art

A display device with a touch panel to which an input can be done with afinger contributes to achieving a user-friendly interactive operabilityby being mounted to a system which controls display content andoperations of an apparatus according to the input. Therefore,information apparatuses to which a touch panels is mounted are rapidlyspread. More specifically, such apparatuses are smartphones, tabletterminals, notebook-type personal computers, and the like.

In the meantime, the surface of the display device on which the touchpanel is loaded is uniformly hard, and a same tactile sense is felt whentouching at any parts displayed on the screen. Thus, it is practicallyimpossible to know which of the parts of the touch panel to touch formaking an effective input or to know whether or not an effective inputis made without looking at the panel. Therefore, it is difficult tooperate those devices only with a tactile sense without looking at thescreen of the display device.

Meanwhile, remote controllers of television set receivers,conventional-type mobile phones, keyboards of personal computers, andthe like include operation keys that are independent from each other.Thus, places of the operation keys can be sensed only with a tactilesense, and it is possible to know that when pressing those operationkeys through the tactile sense. Therefore, it is not so difficult toperform operations only with the tactile sense without looking at thehands by simply remembering the positions and the layout of theoperations keys.

Recently, smartphones have become rapidly spread in the mobile phoneterminal field, and about a half of the currently used mobile phoneterminals have already been replaced with the smartphones. Accordingly,as depicted in “The Dangers of Texting while Walking”, Jun. 25, 2013,Sato Hitoshi, InfoCom, Inc., [searched on Sep. 5, 2013], Internet <URL:http://www.icr.co.jp/newsletter/global_perspective/2013/Gpre201365.html>(Non-Patent Document 1), an action executed while using smartphones, theso-called “smartphoning while walking”, has become a social problem.

It is practically impossible to operate the display device on which thetouch panel is loaded only by a tactile sense without looking at thehands, so that it is necessary to operate the device while carefullylooking at the screen. Therefore, to operate an electronic apparatushaving such display device while walking (or while riding a bicycle,while driving/operating an automobile or the like, for example) has ahigh risk of causing serious injuries and accidents. Actually, there aremany injuries and accidents occurred due to such actions.

Therefore, railway companies, mobile communication companies, electronicapparatus manufactures, and the like are announcing warnings for theaction called “smartphoning while walking”. However, it is only awarning for bringing the attention of the users to such actions in termsof morals. A physical countermeasure for preventing such action whichcan be taken is only to “provide a home door on the platform of trainsfor preventing fall of passengers”, for example. It is currently a factthat there is no definite countermeasure taken for the smartphone itselfin terms of the technical aspect for preventing “smartphoning whilewalking”.

Smartphones can provide comfort in the operation itself by using a touchscreen when browsing Websites and video contents or when using theso-called SNS (Social Network Services). Thereby, the smartphonesexhibit convenience with which a vast amount of information can behandled easily. However, there is no effective technique for making itpossible to operate the smartphones only by a tactile sense withoutlooking at the hands while maintaining the convenience. Those pointsdescribed above are not only for the case of the smartphones but alsofor the case of tablet terminals and the like.

That is, for the information apparatuses such as smartphones, sociallydesired is a technique which makes it possible to present a tactilesense for the user in association with display of a touch screen formaking it possible to operate only with the tactile sense withoutlooking at the hands. Such techniques do not simply make it possible tolighten danger caused due to the action of “smartphoning while walking”but also are effective for those who are suffering from impaired visionto use such devices, for example.

As the tactile sense presenting technique for giving a tactile sense tothe display device, there are following three types: a type whichmechanically oscillates the display device by using a piezoelectricelement, an eccentric motor, or the like; a type that uses the so-calledelectric oscillation phenomenon, which changes friction between a fingerof the user and a tactile sense presentation device by staticelectricity to present a tactile sense (a sense of texture) when tracingthe tactile sense presentation device with a finger; and a type whichdrives an axon of a skin mechanoreceptor of a finger of the user byflowing an electric current to the finger.

“Smartphones for those who are visually impaired are fantastic in thedesigns and functions”, Yuko Matono, Jan. 10, 2011, [searched on Sep. 5,2013, NPO greenz, Internet <URL:http://greenz.jp/2011/01/10/braille_smartphone_voim/> (Non-PatentDocument 2) describes “a smartphone for those who are visuallyimpaired”. This smartphone does not have a normal liquid crystal displaydevice. Instead, this smartphone has a silicone panel which presentsinformation to the user by having protrusions appeared on the surface ofthe device (also has a sound information input/output module and thelike). The silicone panel can present only information of low spatialresolution such as braille. Further, this technique is not forpresenting information that is “associated with display on the touchscreen”.

Japanese Unexamined Patent Publication 2011-248884 (Patent Document 1)describes “electric oscillation for a touch-surface” which uses theelectric oscillation phenomenon. As the feature thereof, it is describedas “a device which includes: a conductive surface; an insulating surfacedisposed on the conductive surface; and a controller which isconstituted in such a manner that a signal is coupled to a user whotouches the device and a tactile sense is felt thereby at least by onefinger of the user sliding on the insulating surface (Claims 1 of PatentDocument 1), wherein “each of a plurality of electrodes is controlled byindependent wirings” (paragraph 0074 in Description of Patent Document 1and FIG. 10A).

That is, the technique depicted in Patent Document 1 intends to make itpossible to present a sense of texture on the touch screen with theabove-described structure.

BRIEF DESCRIPTION

Patent Document 1 discloses a tactile sense presentation device usingelectric oscillation, in which segmented electrodes and independentwirings are provided for each of the electrodes as depicted as “each ofa plurality of electrodes is controlled by independent wirings”(paragraph 0074 in Description of Patent Document 1). However, there arefollowing issues with the tactile sense presentation device depicted inPatent Document 1.

With the technique depicted in Patent Document 1, a space for drawingaround the wirings provided independently for each of the plurality ofelectrodes is required. As a result, the gap between the electrodes forpresenting a sense of texture becomes widened, so that the spatialresolution of the tactile sense presentation device becomes low. InPatent Document 1, it is mentioned as a shortcoming of the techniqueitself that “there is a possibility that the use of a great number ofwirings makes it unscalable as the number of electrodes is increased”(paragraph 0074 in Description of Patent Document 1). That is, theapplicants of that patent acknowledge the issue of the own technique.

Further, since a plurality of wirings are drawn around between theelectrodes for presenting a sense of texture, the shapes of the drawnwirings or the shapes of the electrodes used for presenting a sense oftexture are visually felt by the user when the tactile sensepresentation device of such structure and the display device are used ina superimposed manner. This deteriorates the original display quality ofthe display device.

Further, signals for presenting a sense of texture to each electrode arealso applied to the drawn wirings naturally. Thus, a sense of texturethat is not required originally is presented also in the region wherethe wirings are drawn around.

Further, this technique can only present a sense of texture to the areaswhere the electrodes are embedded in advance. It is necessary torearrange the electrodes for changing the positions and the number ofthe areas for presenting a sense of texture. That is, it is practicallyimpossible to change the positions and the number of the areas forpresenting a sense of texture by corresponding to the displayed objectson the touch screen.

A technique that can overcome each of the above-described points is notdepicted in Non-Patent Documents 1 and 2. That is, there is no techniquewhich makes it possible to perform operations only by a tactile sense byeffectively presenting a sense of texture on the touch screen.

It is an exemplary object of the present invention to provide a tactilesense presentation device, an electronic apparatus, and a tactile sensepresentation method, which make it possible to present a tactile sense(a sense of texture) at a position corresponding to a displayed object,to suppress deterioration of the display quality when the tactile sensepresentation device is superimposed on a display device, and not topresent a sense of texture to an originally unrequired position.

In order to achieve the foregoing object, the tactile sense presentationdevice according to the present invention is characterized to include: asupporting substrate; a plurality of X-electrodes extended in parallelto each other along a first direction on the supporting substrate; aplurality of Y-electrodes extended in parallel to each other along asecond direction on the supporting substrate by being insulated from theX-electrodes; and a driving circuit which applies a first-frequencyvoltage signal to the X-electrode corresponding to information regardinga target region inputted from outside among the plurality ofX-electrodes, and applies a second-frequency voltage signal to theY-electrode corresponding to information regarding the target regioninputted from outside among the plurality of Y-electrodes to generateelectric beat oscillation in the target region by an absolute value of adifference between the first and second frequencies.

In order to achieve the foregoing object, the electronic apparatusaccording to the present invention is characterized to include: atouch-panel type display device which displays a processing resultexecuted by a processor provided therein and accepts an operation inputwhich corresponds to the processing result; and the tactile sensepresentation device according to the present invention (having theabove-described feature), which presents a sense of texturecorresponding to the display of the processing result. Further, a mobileunit which includes the electronic apparatus loaded thereto as anon-vehicle device is also a scope of the present invention.

In order to achieve the foregoing object, the present invention providesthe tactile sense presentation method used with the tactile sensepresentation device which includes: a supporting substrate; a pluralityof X-electrodes extended in parallel to each other along a firstdirection on the supporting substrate; and a plurality of Y-electrodesextended in parallel to each other along a second direction on thesupporting substrate by being insulated from the X-electrodes, wherein:a control unit gives information regarding a target region inputted fromoutside to a driving circuit; and the driving circuit applies afirst-frequency voltage signal to the X-electrodes corresponding to thetarget region; and applies a second-frequency voltage signal to theY-electrodes corresponding to the target region to generate electricbeat oscillation in the target region by an absolute value of adifference between the first and second frequencies.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an explanatory chart showing the structure of a tactile sensepresentation device according to a first basic embodiment of the presentinvention;

FIG. 2 is an explanatory chart showing a driving method of the tactilesense presentation device shown in FIG. 1;

FIG. 3 is an explanatory chart showing a sectional-view model of thetactile sense presentation device shown in FIG. 1 and FIG. 2;

FIG. 4 is a graph acquired by measuring the relation between thethreshold values of the amplitudes of the voltage signals required forthe user to sense the changes in the tactile sensation and thefrequencies of the attraction worked on a finger in the tactile sensepresentation device shown in FIG. 1 and FIG. 2;

FIG. 5 is an explanatory chart showing the structure of a tactile sensepresentation device according to a second basic embodiment of thepresent invention;

FIG. 6 is an explanatory chart showing a driving method of the tactilesense presentation device shown in FIG. 5;

FIG. 7 is an explanatory chart showing each region on a display surfaceof the tactile sense presentation device shown in FIG. 5 and FIG. 6;

FIG. 8 is a graph showing the relation between the frequencies appliedto the X-electrodes as well as the Y-electrodes and a tactile sense inthe tactile sense presentation device shown in FIG. 1 and FIG. 2;

FIG. 9 is an explanatory chart showing the structure of a tactile sensepresentation device according to a third basic embodiment of the presentinvention;

FIG. 10 is an explanatory chart showing a driving method of the tactilesense presentation device shown in FIG. 9;

FIG. 11 is an explanatory chart showing the structure of a tactile sensepresentation device according to a fourth basic embodiment of thepresent invention;

FIG. 12 is an explanatory chart showing a driving method of the tactilesense presentation device shown in FIG. 11;

FIGS. 13A to 13C show explanatory charts showing voltage signalsgenerated by an X-electrode driving circuit and a Y-electrode drivingcircuit in the tactile sense presentation device shown in FIG. 11 andFIG. 12, in which FIG. 13A shows frequency f₆ of the voltage signalsgenerated by the X-electrode driving circuit and applied to theX-electrode, FIG. 13B shows a waveform of the voltage signal generatedby the X-electrode driving circuit and applied to the X-electrode, andFIG. 13C shows a waveform of the voltage signal generated by theY-electrode driving circuit and applied to the Y-electrode,respectively;

FIG. 14 is an explanatory chart showing the attraction F worked on afinger generated in a target region as a result of applying the voltagesignals shown in FIG. 13A to FIG. 13C to the X-electrodes and theY-electrodes which overlap with the target region in the tactile sensepresentation device shown in FIG. 11 and FIG. 12;

FIG. 15 is an explanatory chart showing the structure of a tactile sensepresentation device according to a fifth basic embodiment of the presentinvention;

FIGS. 16A to 16C show explanatory charts showing voltage signalsgenerated by an X-electrode driving circuit and a Y-electrode drivingcircuit in the tactile sense presentation device shown in FIG. 15, inwhich FIG. 16A shows frequency f₇ of the voltage signals generated bythe X-electrode driving circuit and applied to the X-electrode, FIG. 16Bshows a waveform of the voltage signal generated by the X-electrodedriving circuit and applied to the X-electrode, and FIG. 16C shows awaveform of the voltage signal generated by the Y-electrode drivingcircuit and applied to the Y-electrode, respectively;

FIG. 17 is an explanatory chart showing the attraction F worked on afinger generated in a target region as a result of applying the voltagesignals shown in FIG. 16A to FIG. 16C to the X-electrodes and theY-electrodes which overlap with the target region in the tactile sensepresentation device shown in FIG. 15;

FIG. 18 is an explanatory chart showing the structure of a tactile sensepresentation device according to a first exemplary embodiment of thepresent invention;

FIG. 19 is a plan view showing specific shapes of a supportingsubstrate, the X-electrode, and the Y-electrode of the tactile sensepresentation device shown in FIG. 18;

FIGS. 20A and 20B show explanatory charts showing enlarged views of thestructure of a connection part of the X-electrode and a connection partof the Y-electrode shown in FIG. 19, in which FIG. 20A is a plan viewshowing a connection part of the X-electrode and a connection part ofthe Y-electrode shown as a block A in FIG. 19, and FIG. 20B is asectional view taken along a line A-A′ of FIG. 20A;

FIG. 21 is an explanatory chart showing a more detailed structure of anX-electrode driving circuit (a Y-electrode driving circuit) of thetactile sense presentation device shown in FIG. 18;

FIG. 22 is a time chart showing operations of the X-electrode drivingcircuit shown in FIG. 21;

FIG. 23 is an explanatory chart showing the structure of a tactile sensepresentation device according to a second exemplary embodiment of thepreset invention;

FIG. 24 is a plan view showing specific shapes of the X-electrode andthe Y-electrode shown in FIG. 23;

FIG. 25 is a plan view showing specific shapes of the X-electrode andthe Y-electrode shown in FIG. 23 from a different point of view withrespect to that of FIG. 24;

FIG. 26 is an explanatory chart showing the structure of a tactile sensepresentation device according to a third exemplary embodiment of thepreset invention;

FIGS. 27A and 27B show explanatory charts showing enlarged views of thestructure of a connection part of the X-electrode and a connection partof the Y-electrode shown in FIG. 26, in which FIG. 27A is a plan viewshowing a connection part of the X-electrode and a connection part ofthe Y-electrode, and FIG. 27B is a sectional view taken along a lineB-B′ of FIG. 27A;

FIG. 28 is an explanatory chart showing the structure of a tactile sensepresentation device according to a fourth exemplary embodiment of thepreset invention;

FIGS. 29A and 29B show explanatory charts showing enlarged views of thestructure of a connection part of the X-electrode and a connection partof the Y-electrode shown in FIG. 28, in which FIG. 29A is a plan viewshowing a connection part of the X-electrode and a connection part ofthe Y-electrode, and FIG. 29B is a sectional view taken along a lineC-C′ of FIG. 29A;

FIG. 30 is an explanatory chart showing the structure of an electronicapparatus according to an applied embodiment of the present invention;and

FIG. 31 is an explanatory chart showing the structure of a mobile unitaccording to an applied embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Basic Embodiment

Hereinafter, the structure of a first basic embodiment will be describedby referring to accompanying drawing FIG. 1.

A tactile sense presentation device 10 according to the first basicembodiment includes: a supporting substrate 11; a plurality ofX-electrodes 12 extended in parallel to each other along a firstdirection on the supporting substrate; a plurality of Y-electrodes 13extended in parallel to each other along a second direction on thesupporting substrate by being insulated from the X-electrodes; anddriving circuits (an X-electrode driving circuit 14, a Y-electrodedriving circuit 15) which apply a first-frequency voltage signal to theX-electrode corresponding to information regarding the target regioninputted from outside among the plurality of X-electrodes, apply asecond-frequency voltage signal to the Y-electrode corresponding toinformation regarding the target region inputted from outside among theplurality of Y-electrodes, and generate electric beat oscillation in thetarget region by an absolute value of a difference between the first andsecond frequencies.

Note here that the first and second frequencies are 500 Hz or more, andthe absolute value of the difference between the first and secondfrequencies is larger than 10 Hz and less than 1000 Hz. Further, thedriving circuits have a function which ground the electrodes to whichthe first-frequency voltage signal is not applied among the plurality ofX-electrodes and the electrodes to which the second-frequency voltagesignal is not applied among the plurality of Y-electrodes or apply adirect-current voltage to those electrodes.

The above-described structure enables the tactile sense presentationdevice 10 to effectively present a sense of texture to the target regionon the tactile sense presentation device 10 without presenting a tactilesense (a sense of texture) to the irrelevant part. Hereinafter, thiswill be described in more details.

FIG. 1 is an explanatory chart showing the structure of the tactilesense presentation device 10 according to the first base embodiment ofthe present invention. In the tactile sense presentation device 10,formed are a plurality of X-electrodes 12 extended on the planarsupporting substrate 11 along the x direction and a plurality ofY-electrodes 13 extended on the supporting substrate 11 along the ydirection that is orthogonal to the X-electrodes 12.

The X-electrodes 12 and the Y-electrodes 13 intersect with each other atthe intersection parts via an insulating film, and electric insulationbetween the both is maintained. Further, an insulating film (not shown)is formed on the X-electrodes 12 and the Y-electrodes 13 to electricallyinsulate between the X-electrodes 12 and the finger and between theY-electrodes 13 and the finger when the user touches the tactile sensepresentation device 10 from the above. The sectional structure of thetactile sense presentation device 10 will be described later.

The X-electrode driving circuit 14 is connected to each of theX-electrodes 12, the Y-electrode driving circuit 15 is connected to eachof the Y-electrodes 13, and the X-electrode driving circuit 14 and theY-electrode driving circuit 15 are connected to a control unit 16. Thecontrol unit 16 controls the X-electrode driving circuit 14 and theY-electrode driving circuit 15 based on the information regarding thetarget region inputted from outside (e.g., a processor which controlsactions of the electronic apparatus), to which a sense of texture is tobe presented.

This structure enables the tactile sense presentation device 10 topresent a sense of texture in a whole region including all theintersection parts between the X-electrodes 12 and the Y-electrodes 13and in a prescribed part of region.

FIG. 2 is an explanatory chart showing a driving method of the tactilesense presentation device 10 shown in FIG. 1. Note here that each of theX-electrodes 12 and the Y-electrodes 13 is discriminated with differentreference codes that are applied to each of the electrodes. That is, ina case shown in FIG. 2, twenty-eight X-electrodes 12 and forty-sixY-electrodes 13 are formed on the supporting substrate 11. Each of thoseX-electrodes 12 is referred to as X₀₀ to X₂₇ from the bottom to the top,and each of those Y-electrodes 13 is referred to as Y₀₃ to Y₄₈ from theright towards the left direction.

Further, the region to which a sense of texture is to be presented isreferred to as a target region 17. The target region 17 is a range ofX₁₁ to X₁₄ regarding the X-electrodes 12 and a range of Y₂₄ to Y₂₇regarding the Y-electrodes 13. The control unit 16 supplies controlsignals to the X-electrode driving circuit 14 and the Y-electrodedriving circuit 15 based on the information regarding the target region17 given from outside.

Upon receiving the control signals, the X-electrode driving circuit 14applies a voltage signal of frequency f₁=1000 Hz to X₁₁ to X₁₄ and theY-electrode driving circuit 15 applies a voltage signal of frequencyf₂=1240 Hz to Y₂₄ to Y₂₇. Regarding the X-electrodes 12 and theY-electrodes 13 which do not correspond to those ranges, the X-electrodedriving circuit 14 and the Y-electrode driving circuit 15 ground thoseelectrodes in the case shown in FIG. 2 in order to prevent the voltagesfrom being induced by capacitance coupling of the electrodes.Alternatively, a direct-current voltage may be applied instead ofgrounding.

By applying the above-described signals to the X-electrodes 12 and theY-electrodes 13 and the surface of the tactile sense presentation device10 is traced by a finger, a sense of texture is felt only in the targetregion 17 where X₁₁ to X₁₄ and Y₂₄ to Y₂₇ intersect with each other.

By arbitrarily selecting the electrodes to apply the voltage signals, asense of texture can be presented to an arbitrary prescribed region.Further, through selecting all the X-electrodes and all theY-electrodes, it is also possible to present a sense of texture to thewhole region including all the intersection parts between theX-electrodes and the Y-electrodes.

The inventors of the present invention have verified by experiments thata sense of texture is not presented in the region acquired by excludingthe target region 17 from the region on the electrodes of X₁₁ to X₁₄ aswell as in the region acquired by excluding the target region 17 fromthe region on the electrodes of Y₂₄ to Y₂₇. That is, the inventors ofthe present invention have verified that fingers of the human beings donot feel a sense of texture in a case where the frequency of the voltagesignals applied to the electrodes is 1000 Hz or 1240 Hz.

Meanwhile, in the target region 17, the X-electrode to which the voltagesignals of f₁=1000 Hz are applied and the Y-electrode to which thevoltage signals of f₂=1240 Hz are applied are neighboring to each otherso that beat known in the field of wave motions is generated.Hereinafter, a mechanism with which a sense of texture is presented bythe beat will be described.

FIG. 3 is an explanatory chart showing a sectional-view model of thetactile sense presentation device 10 shown in FIG. 1 and FIG. 2. Asdescribed above, a plurality of X-electrodes 12 and a plurality ofX-electrodes 13 are disposed on the flat supporting substrate 11 (notshown in FIG. 3) to be neighboring to each other. A singlefinger-modeled electrode 18 is disposed at a position opposing to thetwo X-electrodes 12 and the two Y-electrodes 13 disposed within thetarget region 17 among the X-electrodes 12 and the Y-electrodes 13. Ahuman body exhibits a grounding effect, so that the electrode 18 can bemodeled to be grounded via a resistance 19 having a resistance value R.

Now, a voltage signal V₁ expressed as V₁=A cos(2πf₁t) is applied to theX-electrodes 12 within the target region 17. The amplitude of thevoltage signal V₁ is A, the frequency is f₁, and t shows the time.Further, a voltage signal V₂ expressed as V₂=A cos(2πf₂t) is applied tothe Y-electrodes 13 within the target region 17. The amplitude of thevoltage signal V₂ is A that is equivalent to the amplitude of thevoltage signal V₁, and the frequency is f₂.

It is possible to have a parallel flat plate capacitor havingcapacitance C modeled between the electrode 18 and each of theX-electrodes 12 within the target region 17 and to have a parallel flatplate capacitor having capacitance C modeled between the electrode 18and each of the Y-electrodes 13 within the target region 17.

At this time, a voltage V_(P) appeared in the electrode 18 becomesV_(P)=(V₁+V₂)/2 when the resistance value R is sufficiently high.

A static electricity force working between a single X-electrode 12 andthe finger-modeled electrode 18 is expressed as F_(e1) as shown in FIG.3. F_(e1) can be acquired as follows when employing a formula known asexpressing a force working between the electrodes of the parallel flatplate capacitor. Note here that ε is a permittivity, and S is anelectrode area of the parallel flat plate capacitor.

$\begin{matrix}{F_{e\; 1} = {\frac{1}{2ɛ\; S}\left( {C\frac{V_{2} - V_{1}}{2}} \right)^{2}}} & \left( {{Expression}\mspace{14mu} 1} \right)\end{matrix}$

Similarly, F_(e2) can be acquired as follows when a static electricityforce working between a single Y-electrode 13 and the finger-modeledelectrode 18 is expressed as F_(e2) as shown in FIG. 3.

$\begin{matrix}{F_{e\; 2} = {\frac{1}{2ɛ\; S}\left( {C\frac{V_{1} - V_{2}}{2}} \right)^{2}}} & \left( {{Expression}\mspace{14mu} 2} \right)\end{matrix}$

When the pitch between the electrodes is so minute that the electricstatic force F_(e2) and the electric static force F_(e1) cannot bedistinguished by a finger, it can be considered that the total forcewhich is the sum of the individual forces F_(e1) and F_(e2) works on thefinger in a macroscopic manner. The total force F of all the forcesworking on the finger-modeled electrode 18 is F=2(F_(e1)+F_(e2)) fromFIG. 3. Thus, it can be acquired as follows by using V₁, V₂ describedabove and values of Expression 1 and Expression 2.

$\begin{matrix}{F = {\frac{A^{2}C^{2}}{2ɛ\; S}\left\{ {1 - {\cos \; 2{\pi \left( {f_{1} + f_{2}} \right)}t}} \right\} \left\{ {1 - {\cos \; 2{\pi \left( {f_{1} - f_{2}} \right)}t}} \right\}}} & \left( {{Expression}\mspace{14mu} 3} \right)\end{matrix}$

From Expression 3, it can be seen that the total force F as the sum ofthe individual forces working on the modeled electrode 18 is acquired bymultiplying a periodic function whose value range is [0, 2] and thefrequency is the absolute value of (f₁−f₂) and a periodic function whosevalue range is [0, A²C²/(εS)] and the frequency is (f₁+f₂) together. Thefrequency of the envelope curve is the absolute value of (f₁−f₂).

In the basic embodiment, it is defined as the frequency f₁=1000 Hz andthe frequency f₂=1240 Hz, so that the absolute value of the differencetherebetween is 240 Hz. Thus, the attraction F working on the fingerchanges at 240 Hz as shown in Expression 3. Therefore, when a persontraces the surface of the tactile sense presentation device 10 with afinger, there is a change in the friction force at the frequency of 240Hz. 240 Hz is a frequency at which the mechanoreceptor of the skin ofhuman beings exhibits sensitivity, so that a sense of texture can bepresented thereto.

Further, the inventors of the present invention have verified theexistence of a sense of texture for the frequency of the voltage signal.A same voltage signal was applied to all the X-electrodes 12 andY-electrodes 13 on the supporting substrate 11 and the existence of asense of texture was checked. As a result, it was verified that a senseof texture is felt when the frequency of the voltage signal is largerthan 5 Hz and less than 500 Hz, and that a sense of texture is not feltin a case where the frequency of the voltage signals is out of thisrange.

Further, existence of a sense of texture for the absolute value of thedifference between f₁ and f₂ was experimentally checked by applying thevoltage signal of the frequency f₁ to all the X-electrodes 12 on thesupporting substrate 11 and applying the voltage signal of the frequencyf₂ to all the Y-electrodes 13. As a result, it was verified that a senseof texture was felt when the absolute value of the difference between f₁and f₂ was larger than 10 Hz and less than 1000 Hz and that a sense oftexture was not felt when the absolute value of the difference betweenf₁ and f₂ was 10 Hz or less or 1000 Hz or more.

Based on those results, it is found to be possible to achieve thetactile sense presentation device 10 which presents a sense of textureto the region where the X-electrode to which the voltage signal of thefrequency f₁ is applied and the Y-electrode to which the voltage signalof the frequency f₂ is applied intersect with each other and does notpresent a sense of texture to other regions through setting f₁ and f₂both as 500 Hz or more and setting f₁ and f₂ such that the absolutevalue of the difference between f₁ and f₂ becomes larger than 10 Hz andless than 1000 Hz, provided that the frequency of the voltage signal tobe applied to the X-electrode is f₁ and the frequency of the voltagesignal to be applied to the Y-electrode is f₂.

Further, it is considered that the frequency of the attraction workingon the finger affects for feeling a sense of texture from Expression 3and the facts depicted in the inquiry thereof, so that the inventors ofthe present invention conducted experiments for checking the relationbetween the frequency of the attraction working on the finger andfeeling of a tactile sense. FIG. 4 is a graph showing measured relationsbetween the threshold values of the amplitudes of the voltage signalsrequired for the user to feel the changes in the tactile sense and thefrequencies of the attraction working on the finger with the tactilesense presentation device 10 shown in FIG. 1 and FIG. 2.

The graph of FIG. 4 shows the result acquired by measuring the thresholdvalues of the amplitudes required for feeling changes in the tactilesense by applying a same voltage signal to all the X-electrodes 12 andall the Y-electrodes 13 on the supporting substrate 11 while changingthe frequency. The bottom axis shows the frequencies of the voltagesignals applied to all the X-electrodes 12 and all the Y-electrodes 13,and the left axis shows the threshold values of the amplitudes of thevoltage signal required for feeling the changes in the tactile sense.

In the experiments, the frequency of the attraction working on thefinger of the operator is twice the frequency f₁ of the applied voltagesignal. For deriving that relation, a static electric force F may beacquired by setting the resistance value of the resistance 19 shown inFIG. 3 as a finite value excluding infinity, extremely “0”, and settingboth of the frequencies of the voltage signals applied to theX-electrodes 12 and the Y-electrodes 13 as f₁. In FIG. 4, thefrequencies of the attraction working on the finger are shown in the topaxis. That is, the relation between the frequency of the attractionworking on the finger and the threshold value of the amplitude requiredfor feeling is expressed by the top axis and the left axis of FIG. 4.

From the graph shown in FIG. 4, it can be found that the threshold valuetakes the minimum value when the frequency of the attraction working onthe finger is near 200 Hz. That is, it can be said that the receptor ofthe skin of the human beings feels a sense of texture with the highestsensitivity when the frequency of the attraction working on the fingeris near 200 Hz. Further, not only the fact that the bottom of a valleyin the graph regarding the relation between the threshold value and thefrequency is where the frequency of the attraction working on the fingeris near 200 Hz, it can also be found from the graph of FIG. 4 that thestart and end of a valley is near 10 Hz and 1000 Hz, respectively.

That is, a sense of texture is felt when the frequency of the attractionis within a range of 10 to 1000 Hz. A sense of texture is not felt atthe frequency out of this range, and a sense of friction is felt.

The working effect of the basic embodiment can be described as follows.When a voltage signal of the frequency f₁ is applied to a prescribedX-electrode 12 on the supporting substrate 11 and a voltage signal ofthe frequency f₂ that is different from the frequency f₁ is applied to aprescribed Y-electrode 13, the attraction of the absolute value of thefrequency (f₁−f₂) works on the finger in the target region 17 containingthe intersection part between the X-electrode and the Y-electrode.

Therefore, through setting the absolute value of the frequency (f₁−f₂)to be larger than 10 Hz and less than 1000 Hz, it is possible to presenta sense of texture to the target region 17 constituted by containing theintersection part between the prescribed X-electrode 12 and theprescribed Y-electrode 13.

The attraction of the frequency that is twice the frequency f₁ works onthe finger in the region on the X-electrode excluding the target region17 constituted by containing the intersection part, and the attractionof the frequency that is twice the frequency f₂ works on the finger inthe region on the Y-electrode excluding the target region 17 constitutedby containing the intersection part based on a formula of the forceworking between the electrodes of the parallel flat plate capacitor.

Therefore, through setting both f₁ and f₂ to be 500 Hz or more, theattraction of 1000 Hz or more works on the finger both in the region onthe prescribed X-electrode and in the region on the Y-electrodeexcluding the target region 17 constituted by containing theintersection part between the prescribed X-electrode and the prescribedY-electrode. Thus, a sense of texture is not presented.

Through the above-described working effect, following issues can beovercome. With an existing tactile sense presentation device, a spacefor drawing around a plurality of independent wirings for each electrodefor presenting a sense of texture is required. As a result, the gapbetween the electrodes for presenting a sense of texture becomes wide sothat the spatial resolution of the tactile sense presentation devicebecomes low. In the basic embodiment, the electrodes for presenting asense of texture also functions as the wirings, so that the spatialresolution can be increased.

Further, the first basic embodiment makes it possible for the shape ofthe electrodes to be hardly recognized. Thus, when it is used bysuperimposed with a display device such as a liquid crystal displaydevice, deterioration in the original display quality of the displaydevice can be suppressed. Further, while the existing tactile sensepresentation device has such an issue that an originally unnecessarysense of texture is presented in the regions where the wirings are drawnaround, the basic embodiment makes it possible to overcome such issue aswell.

Second Basic Embodiment

Instead of the structure of the first basic embodiment described above,in a second basic embodiment of the present invention, the drivingcircuits (an X-electrode driving circuit 114, a Y-electrode drivingcircuit 115) have a function which applies a third-frequency voltagesignal to the electrodes on which the first-frequency voltage signal isnot applied among a plurality of X-electrodes and to the electrodes onwhich the second-frequency voltage signal is not applied among aplurality of Y-electrodes. The third frequency is 2.5 Hz or more and 5Hz or less, or 500 Hz or higher. The absolute value of the differencebetween the third frequency and the first frequency and the absolutevalue of the difference between the third frequency and the secondfrequency are both 10 Hz or less, or 1000 Hz or more.

Not only making it possible to acquire the same effects as those of thefirst basic embodiment, this structure also makes it possible to preventa phenomenon with which a tactile sense presented outside of the targetregion forms a shape called cross hairs having the target region as thecenter.

This will be described in more details hereinafter.

FIG. 5 is an explanatory chart showing the structure of a tactile sensepresentation device 110 according to the second basic embodiment of thepresent invention. The tactile sense presentation device 110 includesmany of the same structures as those of the first basic embodiment.Therefore, same names and reference numerals as those of the first basicembodiment are applied to the same components, and explanations thereofare to be omitted.

In the tactile sense presentation device 110, the supporting substrate11, the X-electrodes 12, the Y-electrodes 13, and the control unit 16are the same as those of the first basic embodiment. Further, anX-electrode driving circuit 114 different from that of the first basicembodiment is connected to each of the X-electrodes 12, and aY-electrode driving circuit 115 different from that of the first basicembodiment is connected to each of the Y-electrodes 13.

The tactile sense presentation device 10 according to the first basicembodiment implements the tactile sense presentation device whichpresents a sense of texture to the target region 17 where theX-electrode 12 to which the voltage signal of the frequency f₁ isapplied and the Y-electrode 13 to which the voltage signal of thefrequency f₂ is applied intersect with each other and does not present asense of texture to the other regions. However, with this tactile sensepresentation device 10, the tactile sense in the region other than thetarget region 17 is not considered to be equivalent within that region.

Defining that the tactile sense in the region where the X-electrode andthe Y-electrode are grounded as a reference tactile sense, a sense offriction is felt strongly with respect to the reference tactile sense inthe region excluding the target region 17 from the region on theelectrodes of X₁₁ to X₁₄ shown in FIG. 2, i.e., a sense of friction ispresented. Similarly, a sense of friction is presented in the regionexcluding the target region 17 from the region on the electrodes of Y₂₄to Y₂₇.

As a result, the tactile sense presentation device 10 according to thefirst basic embodiment presents cross hairs by having the target region17 as the center. The cross hairs can be considered to have an effect asa guide for finding the target region 17. However, it can also beconsidered as an issue in view of the versatility for presenting atactile sense.

A sense of texture is normally generated due to minute protrusions anddents on the surface of an object. For example, when a surface of eachof the materials such as cloth, paper, shark skin, glass, and sandpaperis traced by a finger, differences in a sense of texture can be felt.Meanwhile, a sense of friction is normally generated due to a frictionforce between a finger and a surface of an object. For example, in acase where a surface of glass is traced by a dry finger and a case wherethe surface of glass is traced by a damp finger, a weak sense offriction is felt in the former case while a strong sense of friction isfelt in the latter case. There is no specific change in a sense oftexture between the both cases, and it is possible to feel that theobject is glass in both cases.

The second basic embodiment of the present invention overcomes suchissue, and presents the tactile sense presentation device 10 which makesit possible to equalize a sense of friction in the region where a senseof texture is not presented and equalizes a tactile sense in the regionwhere a sense of texture is not presented.

FIG. 6 is an explanatory chart showing a driving method of a tactilesense presentation device 110 shown in FIG. 5. More specifically, it isfor describing actions of the X-electrode driving circuit 114 and theY-electrode driving circuit 115 according to the basic embodiment.Reference numerals of each of the electrodes are same as those shown inFIG. 2. The target region 17 to which a sense of texture is to bepresented is the same as that of FIG. 2. It is the range of X₁₁ to X₁₄for the X-electrodes 12 and the range of Y₂₄ to Y₂₇ for the Y-electrodes13.

The X-electrode driving circuit 114 applies a voltage signal of thefrequency f₁=1000 Hz to X₁₁ to X₁₄ which overlap with the target region17 among a plurality of X-electrodes 12 and applies a voltage signal ofthe frequency f₅=3000 Hz to the other X-electrodes 12. The Y-electrodedriving circuit 115 applies a voltage signal of the frequency f₂=1240 Hzto Y₂₄ to Y₂₇ which overlap with the target region 17 among a pluralityof Y-electrodes 13 and applies a voltage signal of the frequency f₅=3000Hz to the other Y-electrodes 13.

When the above-described signals are applied to the X-electrodes and theY-electrodes, a sense of texture is felt only in the target region 17when the surface of the tactile sense presentation device 110 is tracedby a finger. Further, an equivalent sense of friction is presented tothe regions other than the target region 17.

FIG. 7 is an explanatory chart showing each region on the tactilepresenting surface of the tactile sense presentation device 110 shown inFIGS. 5 and 6. In FIG. 7, the tactile presenting surface of the tactilesense presentation device 110 is divided into nine regions of (1) to(9). The target region 17 corresponds to the region (5). In this region,the voltage signal of the frequency f₁=1000 Hz is applied to theX-electrodes 12 and the voltage signal of the frequency f₂=1240 Hz isapplied to the Y-electrodes 13. Thus, as described in the first basicembodiment, beat of 240 Hz is generated so that a sense of texture ispresented thereby.

In the regions (1), (3), (7), and (9), a signal voltage of the frequencyf₅=3000 Hz is applied to the X-electrodes 12 and the Y-electrodes 13. Asa result of the experiments, a sense of texture was not presented inthose regions but a sense of friction was presented.

In the regions (2) and (8), a signal voltage of the frequency f₅=3000 Hzis applied to the X-electrodes 12 and a signal voltage of the frequencyf₂=1240 Hz is applied to the Y-electrodes 13. The absolute value of thedifference between f₅ and f₂ is 1760 Hz. As a result of the experiments,a sense of texture was not presented in those regions but a sense offriction was presented.

In the regions (4) and (6), a signal voltage of the frequency f₁=1000 Hzis applied to the X-electrodes 12 and a signal voltage of the frequencyf₅=3000 Hz is applied to the Y-electrodes 13. The absolute value of thedifference between f₅ and f₁ is 2000 Hz. As a result of the experiments,a sense of texture was not presented in those regions but a sense offriction was presented.

That is, a sense of texture was not presented in all the regionsexcluding the target region 17. Further, senses of friction presented inall the regions except for the target region 17 were equivalent to suchan extent that it is not possible to discriminate those by a tactilesense.

The inventors of the present invention checked existence of sensation byhuman beings regarding existence of sensation of a sense of texture anda sense of friction regarding the frequencies of voltage signals byexperiments. FIG. 8 is a graph showing the relation between thefrequencies applied to the X-electrodes 12 and the Y-electrodes 13 and atactile sense in the tactile sense presentation device 110 shown in FIG.5 to FIG. 7.

Two number lines are drawn in FIG. 8. Those lines show a case wheresignal voltages of different frequencies are applied to the X-electrodes12 and the Y-electrodes 13 and a case where signal voltages of a samefrequency are applied to those. Here, the relation between thefrequencies and a tactile sense of human beings in each of the cases ischecked by referring to the number line of the case drawn on the bottomside where signal voltages of a same frequency are applied.

First, in a case where the frequency is 0 to 2.5 Hz, human beings cannotfeel a sense of texture and a sense of friction. In a case where thefrequency is 2.5 to 5 Hz, human beings cannot feel a sense of texturebut can feel a sense of friction. In a case where the frequency is 5 to500 Hz, human beings can feel a sense of texture but cannot feel a senseof friction. Further, in a case where the frequency is 500 Hz or more,human beings cannot feel a sense of texture but can feel a sense offriction.

Subsequently, the relation between the absolute value of a differencebetween the frequencies of the both and a tactile sense of human beingsin a case of applying signal voltages of different frequencies withwhich beat was generated in the X-electrodes 12 and the Y-electrodes 13was checked. The result thereof is drawn as a number line on the upperside in FIG. 8.

In a case where the absolute value of the difference in the frequenciesis 0 to 5 Hz, human beings cannot feel a sense of texture and a sense offriction. In a case where the absolute value of the difference in thefrequencies is 5 to 10 Hz, human beings cannot feel a sense of texturebut can feel a sense of friction. In a case where the absolute value ofthe difference in the frequencies is 10 to 1000 Hz, human beings canfeel a sense of texture but cannot feel a sense of friction. Further, ina case where the absolute value of the difference in the frequencies is1000 Hz or more, human beings cannot feel a sense of texture but canfeel a sense of friction.

According to the results of the experiments described above, with thetactile sense presentation device 110 of the basic embodiment, each off₁, f₂, and f₅ is defined to be a value satisfying each of followingconditions provided that the frequency of the signal voltage supplied tothe X-electrodes 12 that overlap with the target region 17 is f₁, thefrequency of the signal voltage supplied to the Y-electrodes 13 thatoverlap with the target region 17 is f₂, and the frequency of the signalvoltage supplied to the other X-electrodes 12 and Y-electrodes 13 is f₅.

-   -   f₁ an f₂ are both 500 Hz or more    -   Absolute value of the difference between f₁ and f₂ is larger        than 10 Hz and less than 1000 Hz    -   f₅ is between 2.5 and 5 Hz, both inclusive, or 500 Hz or more    -   Absolute value of the difference between f₅ and f₁ is 10 Hz or        less or 1000 Hz or more    -   Absolute value of the difference between f₅ and f₂ is 10 Hz or        less or 1000 Hz or more

Through satisfying the above-described conditions, the tactile sensepresentation device 110 can present a sense of texture to the targetregion 17 where the X-electrodes 12 to which the signal voltage of thefrequency f₁ is applied and the Y-electrodes 13 to which the signalvoltage of the frequency f₂ is applied intersect with each other, andcan present an equivalent sense of friction to the other regions.

The tactile sense presentation device 110 according to the embodimentcan present a sense of texture only to the target region 17 and presentan equivalent sense of friction to the other regions. That is, it ispossible to present a different tactile sense only to a prescribedregion while a tactile sense on the background of the tactile sensepresenting surface is equivalent. This makes it possible to increase theeffect of presenting the tactile sense.

Third Basic Embodiment

Instead of the structure of the first basic embodiment described above,in a third basic embodiment of the present invention, the drivingcircuits (an X-electrode driving circuit 214, a Y-electrode drivingcircuit 215) have a function which applies a first-frequency voltagesignal to the X-electrodes which correspond to a first target regionwhile applying a second-frequency voltage signal to the Y-electrodeswhich correspond to the first target region and, at the same time,applies a third-frequency voltage signal to the X-electrodes whichcorrespond to a second target region while applying a fourth-frequencyvoltage signal to the Y-electrodes which correspond to the second targetregion.

Regarding each of those frequencies, all of the first to fourthfrequencies are 500 Hz or higher. The absolute value of the differencebetween the first and second frequencies and the absolute value of thedifference between the third and fourth frequencies are both larger than10 Hz and less than 1000 Hz, and the absolute value of the differencebetween the first and fourth frequencies and the absolute value of thedifference between the second and third frequencies are both 10 Hz orless, or 1000 Hz or more.

Not only making it possible to acquire the same effects as those of thefirst basic embodiment, this structure also makes it possible to presenta sense of texture to each of the target regions even when a pluralityof target regions are designated. This will be described in more detailshereinafter.

FIG. 9 is an explanatory chart showing the structure of a tactile sensepresentation device 210 according to the third basic embodiment of thepresent invention. The tactile sense presentation device 210 includesmany of the same structures as those of the first basic embodiment.Therefore, same names and reference numerals as those of the first basicembodiment are applied to the same components, and explanations thereofare to be omitted.

In the tactile sense presentation device 210, the supporting substrate11, the X-electrodes 12, and the Y-electrodes 13 are the same as thoseof the first basic embodiment. Further, an X-electrode driving circuit214 different from that of the first basic embodiment is connected toeach of the X-electrodes 12, and a Y-electrode driving circuit 215different from that of the first basic embodiment is connected to eachof the Y-electrodes 13. Furthermore, a control unit 216 different fromthat of the first basic embodiment is connected to the X-electrodedriving circuit 214 and the Y-electrode driving circuit 215.

In the tactile sense presentation devices 10 and 110 according to thefirst and second basic embodiments, there is only one target region 17to which a sense of texture is to be presented. However, the tactilesense presentation device 210 according to this basic embodimentpresents a sense of texture to a plurality of individual regions on thesurface. The control unit 216 supplies control signals to theX-electrode driving circuit 214 and the Y-electrode driving circuit 215regarding each of the plurality of regions.

FIG. 10 is an explanatory chart showing a driving method of the tactilesense presentation device 210 shown in FIG. 9. More specifically, it isfor describing actions of the X-electrode driving circuit 214 and theY-electrode driving circuit 215 according to the basic embodiment. Notehere that the regions for presenting a sense of texture are twoindividual regions 17 a and 17 b.

The X-electrode driving circuit 214 applies a signal voltage of thefrequency f₁=1000 Hz to the X-electrodes that overlap with the region 17a on a plan view, and applies a signal voltage of the frequency f₃=2480Hz to the X-electrodes that overlap with the region 17 b on a plan viewamong a plurality of X-electrodes 12. The Y-electrode driving circuit215 applies a signal voltage of the frequency f₂=1240 Hz to theY-electrodes that overlap with the region 17 a on a plan view, andapplies a signal voltage of the frequency f₄=2240 Hz to the Y-electrodesthat overlap with the region 17 b on a plan view among a plurality ofY-electrodes 13.

When the above-described signals are applied to the X-electrodes 12 andthe Y-electrodes 13, a sense of texture is felt only in the targetregions 17 a and 17 b when the surface of the tactile sense presentationdevice 210 is traced by a finger. This can be described as follows basedon the relation between the frequencies applied to the X-electrodes andthe Y-electrodes and a tactile sense described by referring to FIG. 8.

Signal voltages of 1000 Hz and 1240 Hz are applied to the X-electrodes12 and the Y-electrodes 13, respectively, which overlap with the targetregion 17 a on a plan view, and the absolute value of the differencetherebetween is 240 Hz. Thus, a sense of texture is presented to thetarget region 17 a. Signal voltages of 2480 Hz and 2240 Hz are appliedto the X-electrodes 12 and the Y-electrodes 13, respectively, whichoverlap with the target region 17 b on a plan view, and the absolutevalue of the difference therebetween is 240 Hz. Therefore, a sense oftexture is also presented to the target region 17 b.

Meanwhile, in the region (the region shown as (3) in FIG. 10) where theX-electrodes 12 to which the signal voltage of the frequency f₃=2480 Hzis applied and the Y-electrodes 13 to which the signal voltage of thefrequency f₂=1240 Hz is applied intersect with each other, the absolutevalue of the difference between the frequencies of both signal voltagesis 1240 Hz. Therefore, a sense of texture is not presented.

Further, in the region (the region shown as (4) in FIG. 10) where theX-electrodes 12 to which the signal voltage of the frequency f₁=1000 Hzis applied and the Y-electrodes 13 to which the signal voltage of thefrequency f₄=2240 Hz is applied intersect with each other, the absolutevalue of the difference between the frequencies of both signal voltagesis 1240 Hz. Therefore, a sense of texture is not presented.

Further, all the frequencies f₁ to f₄ are 500 Hz or more, so that asense of texture is not presented in the electrode alone to which thoseare applied. From those results described above, it is found that asense of texture is presented limitedly to the target regions 17 a and17 b with the tactile sense presentation device 210.

Based on the results, it is possible to achieve the tactile sensepresentation device 210 which presents a sense of texture to a pluralityof individual regions on the tactile sense presenting surface throughsupplying the voltage signals in such a manner that the absolute valueof the difference between the frequencies of the voltage signals appliedto the X-electrodes 12 and the Y-electrodes 13 forming the intersectionis larger than 10 Hz and less than 1000 Hz in the intersections includedin the target regions 17 a and 17 b to which a sense of texture is to bepresented among the intersection parts of the X-electrodes 12 and theY-electrodes 13 and that the absolute value of the difference betweenthe frequencies of the voltage signals applied to the X-electrodes 12and the Y-electrodes 13 is 10 Hz or less or 1000 Hz or more in the otherintersection parts formed by the X-electrodes 12 and the Y-electrodes 13which form those intersection parts.

That is, the tactile sense presentation device 210 according to thisembodiment is capable of presenting a sense of texture to a plurality oftarget regions 17 a and 17 b isolated from each other on the tactilesense presenting surface, so that the versatility of presenting atactile sense can be improved.

The electrode to which input of the voltage signals of the frequenciesf₁ to f₄ is not designated in the third basic embodiment may be groundedor a direct-current voltage may be applied thereto as in the case of thefirst basic embodiment. Further, it is also possible to apply thevoltage signals of the frequencies satisfying the conditions depicted inthe second basic embodiment to the electrodes to which an input of thevoltages signals of any of the frequencies f₁ to f₄ is not designated.

Generalization of Third Basic Embodiment

Actions described in the third basic embodiment will be generalized anddescribed. The third basic embodiment is a case where there are twotarget regions, and two regions existing at diagonal angles of a squarehaving the four regions (1) to (4) shown in FIG. 10 as the vertexes aretaken as the target regions.

Even in a case where the number of target regions is an arbitrary numberof 2 or more or the above-described condition of “existing at thediagonal angles” is excluded, it is also possible to present a sense oftexture to each of a plurality of arbitrary target regions. In thatcase, the voltage signals may be applied to each of the X-electrodes andthe Y-electrodes by determining the frequencies in such a manner thatthe absolute value of the difference between the frequencies of thevoltage signals applied to the X-electrodes and the Y-electrodescontained in the target regions is larger than 10 Hz and less than 1000Hz and that the absolute value of the difference between the frequenciesof the voltage signals applied to the X-electrodes and the Y-electrodesforming the intersection is 10 Hz or less or 1000 Hz or more in theother intersection parts excluding the target regions which are formedby the X-electrodes and the Y-electrodes forming the target region.

Fourth Basic Embodiment

In addition to the structure of the first basic embodiment describedabove, in a fourth basic embodiment of the present invention, thedriving circuits (an X-electrode driving circuit 264, a Y-electrodedriving circuit 265) have a function which applies a first-frequencyvoltage signal of 500 Hz or more to the X-electrodes which correspond toinformation regarding a target region inputted from outside among theplurality of X-electrodes and applies a voltage signal of a secondfrequency of 500 Hz or more to the Y-electrodes which correspond toinformation regarding the target region among the plurality ofY-electrodes. Further, the driving circuits chronologically change atleast either one of the frequencies out of the first and secondfrequencies within a range that is not lower than 500 Hz.

Note here that there are a first period where the absolute value of thedifference between the first frequency and the second frequency islarger than 10 Hz and less than 1000 Hz and a second period where theabsolute value of the difference between the first frequency and thesecond frequency is 10 Hz or less or 1000 Hz or more. Further, the firstperiod and the second period are set alternately.

With this structure, it is possible to present various kinds of tactilesenses that can be more easily felt in addition to achieving the sameeffects as those of the first basic embodiment. This will be describedin more details hereinafter.

FIG. 11 is an explanatory chart showing the structure of a tactile sensepresentation device 260 according to the fourth basic embodiment of thepresent invention. FIG. 12 is an explanatory chart showing a drivingmethod of the tactile sense presentation device 260 shown in FIG. 11.

The tactile sense presentation device 260 includes many of the samestructures as those of the first basic embodiment. Therefore, same namesand reference numerals as those of the first basic embodiment areapplied to the same components, and explanations thereof are to beomitted. More specifically, the tactile sense presentation device 260makes it possible to present many kinds of tactile senses by changingthe static electric force F generated in the target region 17 over thetime.

It is the feature of the tactile sense presentation device 260 to: applya first-frequency voltage signal of 500 Hz or more to the X-electrodeswhich correspond to information regarding the target region 17 inputtedfrom outside among the plurality of X-electrodes 12; apply asecond-frequency voltage signal of 500 Hz or more to the Y-electrodeswhich correspond to information regarding the target region 17 among theplurality of Y-electrodes 13; and chronologically change at least eitherone of both of the frequencies out of the first and second frequencieswithin a range that is not lower than 500 Hz.

With this feature, the tactile sense presentation device 260 accordingto this basic embodiment presents many kinds of tactile senses to thetarget region 17. Further, it is possible with this feature not topresent an unnecessary tactile sense to the regions other than thetarget region while presenting many kinds of tactile senses within thetarget region 17.

Further, the tactile sense presentation device 260 according to thisbasic embodiment has both periods of the first period where the absolutevalue of the difference between the first frequency and the secondfrequency is larger than 10 Hz and less than 1000 Hz and the secondperiod where the absolute value of the difference between the firstfrequency and the second frequency is 10 Hz or less or 1000 Hz or more,and the first period and the second period are alternately set.

This feature of the tactile sense presentation device 260 according tothis basic embodiment makes it possible not to present an unnecessarytactile sense to the regions other than the target region whilepresenting a pulsating sense of texture within the target region 17.

In the tactile sense presentation device 260, the supporting substrate11, the X-electrodes 12, and the Y-electrodes 13 are the same as thoseof the first basic embodiment. Further, an X-electrode driving circuit264 which generates voltage signals different from those of the firstbasic embodiment is connected to each of the X-electrodes 12, and aY-electrode driving circuit 265 which generates voltage signalsdifferent from those of the first basic embodiment is connected to eachof the Y-electrodes 13. Furthermore, a control unit 266 different fromthat of the first basic embodiment is connected to the X-electrodedriving circuit 264 and the Y-electrode driving circuit 265.

FIG. 13 is an explanatory chart showing voltage signals generated by theX-electrode driving circuit 264 and the Y-electrode driving circuit 265in the tactile sense presentation device 260 shown in FIG. 11 and FIG.12. The target region 17 to which a sense of texture is to be presentedis a range of X₁₁ to X₁₄ for the X-electrodes 12 and a range of Y₂₄ toY₂₇ for the Y-electrodes 13. The control unit 266 supplies controlsignals to the X-electrode driving circuit 264 and the Y-electrodedriving circuit 265 based on the information regarding the target region17 supplied from outside.

The X-electrode driving circuit 264 upon receiving the control signalsapplies a voltage signal of the frequency f₆ to the X-electrodes thatoverlap with the target region 17 among a plurality of X-electrodes 12on a plan view and the Y-electrode driving circuit 265 applies a voltagesignal of the frequency f₂ to the Y-electrodes that overlap with thetarget region 17 among a plurality of Y-electrodes 13 on a plan view.

FIG. 13A shows the frequency f₆ of the voltage signal generated by theX-electrode driving circuit 264 and applied to the X-electrodes 12. Thefrequency f₆ changes in accordance with the time. It is f₆=1000 Hz in aperiod of time 0.285 to 0.295, f₆=1240 Hz in a period of time 0.295 to0.305, and f₆=1000 Hz in a period of time 0.305 to 0.315.

FIG. 13B shows a waveform of the voltage signal generated by theX-electrode driving circuit 264 and applied to the X-electrodes 12. Itis a case where f₆=1000 Hz and 1240 Hz, and there is no specific changein the voltage value.

FIG. 13C shows the frequency f₂ of the voltage signal generated by theY-electrode driving circuit 265 and applied to the Y-electrodes 13. Thefrequency f₂ does not change in accordance with the time, and f₂=1240Hz.

FIG. 14 is an explanatory chart showing the attraction F working on afinger, which is generated in the target region 17 as a result ofapplying the voltage signals shown in FIGS. 13A to 13C to theX-electrodes 12 and the Y-electrodes 13 which overlap with the targetregion 17 by the tactile sense presentation device 260 shown in FIG. 11and FIG. 12. The attraction F can be acquired by using Expression 3described above.

FIG. 14 shows the attraction F acquired by a calculation and envelopecurves thereof. The frequencies of the envelope curves, i.e., thefrequencies of the beat, are 240 Hz in the period of the time 0.285 to0.295, 0 Hz in the period of the time 0.295 to 0.305, and 240 Hz in aperiod of the time 0.305 to 0.315.

In the period of the time 0.295 to 0.305, not only the frequency is zerobut also the attraction F is zero. A case where the attraction F is zerois a case where the frequency f₆ of the voltage signal applied to theX-electrode 12 in the period of the time 0.295 to 0.305 is the same asthe frequency f₂ of the Y-electrodes 13 and the phases are alsoequivalent. It is not necessarily essential for the phases of f₆ and f₂to be equivalent.

When the surface of the tactile sense presentation device 260 is tracedby a finger, a sense of texture is felt when the frequency of theattraction F is 240 Hz while a sense of texture is not felt when thefrequency of the attraction F is 0 Hz.

Therefore, the tactile sense presentation device 260 can present atactile sense that varies over the time in the target region 17. Forexample, through setting the frequency f₂ of the voltage signal appliedto the Y-electrodes 13 as f₂=1240 Hz and changing the frequency f₆ ofthe voltage signal applied to the X-electrodes 12 to 1240 Hz by every300 milliseconds for a period of 10 milliseconds by having 1000 Hz asthe reference value, it is possible to present a pulsating sense oftexture.

The advantage peculiar to the tactile sense presentation device 260according to the fourth basic embodiment described above is that it ispossible to present a tactile sense that varies over the time in thetarget region 17 without presenting a sense of texture and pulsation tothe regions other than the target region 17.

That is, the tactile sense presentation device 260 changes the frequencyf₆ of the voltage signal applied to the X-electrode 12 over the time forpresenting a tactile sense that varies over the time in the targetregion 17. However, in the above-described case, the frequency f₆ isconstantly 1000 Hz or more, so that a sense of texture is not generatedand a sense of friction is constant to such an extent that it cannot befelt. Therefore, an unnecessary tactile sense is not presented on theX-electrodes outside the target region 17.

The attraction F same as that shown in FIG. 14 can also be generatedunder following conditions. First, the frequency of the signal voltageto be applied to the X-electrodes 12 is set as 1000 Hz in a period of0.285 to 0.295, as 0 Hz in a period of time 0.295 to 0.305, and as 1000Hz in a period of time 0.305 to 0.315. In the period of time 0.295 to0.305 in this case, the signal voltage is set as a constant value of 0V.

Meanwhile, the frequency of the signal voltage to be applied to theY-electrodes 13 is set as 1240 Hz in a period of 0.285 to 0.295, as 0 Hzin a period of time 0.295 to 0.305, and as 1240 Hz in a period of time0.305 to 0.315. In the period of time 0.295 to 0.305 in this case, thesignal voltage is set as a constant value of 0 V.

That is, in the period of time 0.295 to 0.305, the signal voltage is 0 Vand the frequency is 0 Hz in both for the X-electrodes 12 and theY-electrodes 13. When a tactile sense presentation device 260 is drivenunder such condition, a pulsating sense of texture is presented to thetarget region 17. At the same time, a pulsating sense of texture is alsopresented on the electrodes not belonging to the target region 17, towhich the voltage signal is applied, thereby presenting an originallyunnecessary tactile sense. In this regards, the tactile sensepresentation device 260 does not present an originally unnecessarytactile sense, so that it is advantageous.

The fact that the voltage signals applied to the X-electrodes 12 and theY-electrodes 13 are not limited to 1000 Hz and 1240 Hz with the tactilesense presentation device 260 according to the fourth basic embodimentdescribed above is evident also from the first to third basicembodiments described heretofore. The point is that the voltage signalsto be applied to the X-electrodes 12 and the Y-electrodes 13 may simplybe defined as follows.

That is, f₆ and f₂ are both 500 Hz or more, f₆ is set in such a mannerthat the absolute value of the difference between the both becomeslarger than 10 Hz and less than 1000 Hz in the time where a sense oftexture is desired to be presented to the target region 17, and f₆ isset in such a manner that the absolute value of the difference betweenthe both becomes 10 Hz or less or larger than 1000 Hz in the time wherea sense of texture is not to be presented to the target region 17. Suchconditions may be satisfied.

Further, it is described in the above case to fix f₂ and to change f₆.However, existence of a sense of texture is determined according to theabsolute value of the difference between the frequencies of f₂ and f₆.Thus, it is also possible to change f₂ and to fix f₆ or to change theboth.

Fifth Basic Embodiment

In addition to the structure of the fourth basic embodiment describedabove, a fifth basic embodiment of the present invention is structuredto change at least one frequency out of the first and second frequenciescontinuously according to the time within a range not less than 500 Hz.

With this structure, it is possible to present various kinds of tactilesenses that can be more easily felt in addition to achieving the sameeffects as those of the first basic embodiment. This will be describedin more details hereinafter.

FIG. 15 is an explanatory chart showing the structure of a tactile sensepresentation device 270 according to the fifth basic embodiment of thepresent invention. The tactile sense presentation device 270 hascompletely the same structure as that of the tactile sense presentationdevice 260 described above as the fourth basic embodiment. Only thevoltage signals applied to the X-electrodes 12 and the Y-electrodes 13are different.

That is, in the tactile sense presentation device 270, the supportingsubstrate 11, the X-electrodes 12, and the Y-electrodes 13 are the sameas those of the first basic embodiment. Further, the X-electrode drivingcircuit 264, the Y-electrode driving circuit 265, and the control unit266 are same as those of the fourth basic embodiment. The tactile sensepresentation device 270 according to this embodiment shows anothersetting examples regarding the voltage signals applied to theX-electrodes 12 and the Y-electrodes 13 of the tactile sensepresentation device 260 according to the fourth basic embodimentdescribed above.

FIGS. 16A to 16C are explanatory charts showing voltage signalsgenerated by the X-electrode driving circuit 264 and the Y-electrodedriving circuit 265 in the tactile sense presentation device 270 shownin FIG. 15. The target region 17 to which a sense of texture is to bepresented is a range of X₁₁ to X₁₄ for the X-electrodes 12 and a rangeof Y₂₄ to Y₂₇ for the Y-electrodes 13. The control unit 266 suppliescontrol signals to the X-electrode driving circuit 264 and theY-electrode driving circuit 265 based on the information regarding thetarget region 17 supplied from outside.

The X-electrode driving circuit 264 upon receiving the control signalsapplies a voltage signal of the frequency f₇ to the X-electrodes thatoverlap with the target region 17 among a plurality of X-electrodes 12on a plan view and the Y-electrode driving circuit 265 applies a voltagesignal of the frequency f₂ to the Y-electrodes that overlap with thetarget region 17 among a plurality of Y-electrodes 13 on a plan view.

FIG. 16A shows the frequency f₇ of the voltage signal generated by theX-electrode driving circuit 264 and applied to the X-electrodes 12. Thefrequency f₇ continuously changes in accordance with the time. The valuethereof can be expressed as f₇=1240−(120t/0.05), where t is the time.

FIG. 16B shows a waveform of the voltage signal generated by theX-electrode driving circuit 264 and applied to the X-electrodes 12. Whenthe waveform is expressed with a numerical expression, the voltage ofthe voltage signal is A cos (2πf₇t), where A is the amplitude. That is,regarding the voltage signal, there is no specific change in the voltagevalue while the frequency f₇ changes in accordance with the time.

FIG. 16C shows the frequency f₂ of the voltage signal generated by theY-electrode driving circuit 265 and applied to the Y-electrodes 13. Thisf₂ is the same as the voltage signal generated by the Y-electrodedriving circuit 265 according to the fourth basic embodiment shown inFIG. 13C. That is, f₂=1240 Hz regardless of the time.

FIG. 17 is an explanatory chart showing the attraction F working on afinger, which is generated in the target region 17 as a result ofapplying the voltage signals shown in FIGS. 16A to 16C to theX-electrodes 12 and the Y-electrodes 13 which overlap with the targetregion 17 by the tactile sense presentation device 270 shown in FIG. 15.The attraction F can be acquired by using Expression 3 described above.

FIG. 17 shows the attraction F acquired by a calculation and envelopecurves thereof. The frequencies of the envelope curves, i.e., thefrequencies of the beat, increase as the passage of the time t. Thefrequency at the time 0 is 0 Hz, and it is 120 Hz at the time 0.05.

Through continuously changing the frequency f₇ of the voltage signalapplied to the X-electrodes 12 according to the time t, the attractionof various frequencies can be generated in the target region 17 andvarious senses of texture can be presented to the user. FIG. 16 shows acase of continuously decreasing the frequency f₇ according to the timet. Naturally, however, it is also possible to continuously increase thefrequency according to the time t or to alternately repeat continuousdecrease and increase. In the meantime, a sense of texture and anunnecessary tactile sense are not to be presented outside the targetregion 17.

The fact that the voltage signals applied to the X-electrodes 12 and theY-electrodes 13 are not limited to 1000 Hz and 1240 Hz also with thetactile sense presentation device 270 according to the fifth basicembodiment described above is evident also from the first to third basicembodiments described heretofore. When it is desired to generate varioussenses of texture, the voltage signals to be applied to the X-electrodes12 and the Y-electrodes 13 may simply be defined as follows.

f₇ and f₂ are both 500 Hz or more, f₇ may be changed in such a mannerthat the absolute value of the difference between the both becomeslarger than 10 Hz and less than 1000 Hz in a case where a sense oftexture is desired to be presented to the target region 17, and f₇ maybe changed in such a manner that the absolute value of the differencebetween the both becomes 10 Hz or less or larger than 1000 Hz in a casewhere a sense of texture is not to be presented to the target region 17.

Further, through setting both f₇ and f₂ as 500 Hz or more and variouslychanging f₇ in a range with which the absolute value of the differencebetween the both becomes larger than 10 Hz and less than 1000 Hz,various senses of texture can be presented to the target region 17 andthe presented sense of texture can be felt more easily (i.e., it ispossible to make it conspicuous).

The features described in the fourth and fifth basic embodiments abovecan be used in combination with either one of or both of the second andthird basic embodiments. Further, when an effective touch input is madeon a specific target region, it is also possible to change a sense oftexture to show that.

Effects Achieved by Basic Embodiments

The effects acquired by the five basic embodiments of the presentinvention described above will be summarized. First, with each of thebasic embodiments of the present invention, the space for drawing arounda plurality of independent wirings for each of the tactile presentingelectrodes with the existing techniques becomes unnecessary, so that itis possible to provide a tactile sense presentation device of highspatial resolution.

The reason that the plurality of independent wirings become unnecessaryis because the X-electrodes and the Y-electrodes having the function ofpresenting a tactile sense also function as the drawn wirings. Further,since a sense of texture is presented by using the beat effect betweenthe X-electrodes and the Y-electrodes, a sense of texture is presentedonly in the region where the voltage signals between the X-electrodesand the Y-electrodes overlap with each other and a sense of texture isnot presented only with one of the voltage signals applied to theX-electrodes or the Y-electrodes.

Next, with each of the basic embodiments of the present invention, aplurality of independent drawn wirings provided for each of the tactilesense presenting electrodes with the existing techniques becomesunnecessary. Therefore, it is possible to suppress deterioration in thedisplay quality of the display device when the tactile sensepresentation device is used by being superimposed on the display device.

Further, signals for presenting a sense of texture are also applied tothe wirings connected towards each of the tactile sense presentationelectrodes with the existing techniques, so that originally unnecessarysense of texture is presented to the regions where the wirings are drawnaround. Each of the basic embodiments of the present invention makes itpossible not to present “originally unnecessary sense of texture” tounrequired regions.

Further, with the second basic embodiment of the present invention, adifferent tactile sense can be presented only to a desired region whilethe tactile senses of the background on the tactile sense presentingsurface are equivalent. Thus, the tactile sense presenting effect can beincreased. The reason thereof is that the voltage signals are applied tothe X-electrodes and the Y-electrodes which do not correspond to thetarget region in such a manner that a sense of texture is not presentedand an equivalent sense of friction is presented to the region where itis not intended to present a sense of texture.

Further, with each of the basic embodiments of the present invention, adetailed tactile sense presentation pattern can be presented on thetactile sense presenting surface. The tactile sense presentation deviceof the present invention is for presenting a sense of texture bychanging the friction between the finger and the tactile sensepresentation device so that it is not necessary to mechanicallyoscillate the tactile sense presentation device for presenting a senseof texture. Thus, the use of the present invention makes it possible toclearly show the edges of the region to which a sense of texture ispresented.

In other words, the tactile sense presentation device of the presentinvention exhibits such a feature that blurring of the edges of theregion to which a sense of texture is to be presented is extremelysmall. When the tactile sense presentation device itself is mechanicallyoscillated, the oscillation is easily transmitted through a solid body.Thus, it is considered to be difficult to present a sense of texture toone point out of neighboring two points and not to present a sense oftexture to the other one point.

In the meantime, it is possible with each of the basic embodiments ofthe present invention to generate the attraction by the beat only in theregion where a prescribed X-electrode to which the voltage signal of thefrequency f₁ is applied and a prescribed Y-electrode to which thevoltage signal of the frequency f₂ is applied are neighboring to eachother, i.e., only in the region where the X-electrode and theY-electrode in the peripheral part of the intersection part between theprescribed X-electrode and the prescribed Y-electrode are neighboring toeach other. Therefore, it is possible to achieve such a feature that asense of texture is presented to one point out of neighboring two pointsand a sense of texture is not presented to the other one point.

Due to the combination of the effect of having small blurring and theeffect of having high spatial resolution described above, each of thebasic embodiments of the present invention can achieve the effect ofmaking it possible to present a detailed tactile sense presentationpattern on the tactile presenting surface. As shown as the third basicembodiment, even when a plurality of target regions are designated, itis possible to present a clear sense of texture to each of thoseregions.

First Exemplary Embodiment Supporting Substrate and Electrodes

The structures for more specifically implementing the first to fifthbasic embodiments of the present invention described heretofore will bedescribed hereinafter.

In addition to the structures of the first to fifth basic embodiments ofthe present invention, in a first exemplary embodiment of the presentinvention, X-electrodes 312 and Y-electrodes 313 are both formed bycoupling a plurality of rhombic electrodes in a form like a string ofbeads via a connection parts, the X-electrodes and the Y-electrodesoverlap with each other at the connection parts, and the rhombic partsof the X-electrodes and the Y-electrodes are neighboring to each otheron a plan view.

Further, regarding either the X-electrodes or the Y-electrodes, aplurality of electrodes are connected by the connection parts that areformed integrally by identical material as those of a plurality ofelectrodes. Regarding the other one of the X-electrodes or theY-electrodes, a bridge electrode is used for electrically connecting thepart where a plurality of electrodes are disconnected. Further, aplurality of X-electrodes and a plurality of Y-electrodes are disposedin parallel to each other at a pitch smaller than 5 mm.

Not only making it possible to acquire the same effects as those of thefirst to fifth basic embodiments, this structure also makes it possibleto present a sense of texture more strongly by generating stronger beatbetween the X-electrodes and the Y-electrodes.

This will be described in more details hereinafter.

FIG. 18 is an explanatory chart showing the structure of a tactile sensepresentation device 310 according to the first exemplary embodiment ofthe present invention. In the tactile sense presentation device 310, aplurality of X-electrodes 312 extended in the x direction on a plan typesupporting substrate 311 and a plurality of Y-electrodes 313 extended inthe y direction orthogonal to the X-electrodes 312 on the supportingsubstrate 311 are formed.

The X-electrodes 312 and the Y-electrodes 313 intersect with each otherin the intersection parts thereof via an insulating film, and electricinsulation between the both is maintained. Further, an insulating filmis formed on the X-electrodes 312 and the Y-electrodes 313 forelectrically insulating between the X-electrodes 312 and a finger andbetween the Y-electrodes 313 and a finger when a user touches thedisplay surface of the tactile sense presentation device 310 by thefinger from the above.

An X-electrode driving circuit 314 is connected to each of theX-electrodes 312, a Y-electrode driving circuit 315 is connected to eachof the Y-electrodes 313, and the X-electrode driving circuit 314 and theY-electrode driving circuit 315 are connected to a control unit 316. Thecontrol unit 316 controls the X-electrode driving circuit 314 and theY-electrode driving circuit 315 based on the information regarding theregion to which a sense of texture is to be presented.

FIG. 19 is a plan view showing specific shapes of the supportingsubstrate 311, the X-electrodes 312, and the Y-electrodes 313 of thetactile sense presentation device 310 shown in FIG. 18. In FIG. 19, theX-electrodes 312 and the wirings thereof are shown with dotted lines,while the Y-electrodes 313 and the wirings thereof are shown with solidlines.

The X-electrodes 312 are formed by coupling a plurality of rhombicelectrodes via connection parts in a form like a string of beads. Thatis, a single X-electrode 312 is formed by electrically connectingrhombic electrodes neighboring to each other on the left and right sidesvia a connection part, and it is extended in the x direction. TheX-electrodes 312 are disposed at a pitch of 2 mm in the y-axisdirection. That is, the pitch between the X-electrodes 312 is 2 mm.

Similarly, the Y-electrodes 313 are formed by coupling a plurality ofrhombic electrodes via connection parts in a form like a string ofbeads. That is, a single Y-electrode 313 is formed by electricallyconnecting rhombic electrodes neighboring to each other on the top andbottom sides via a connection part, and it is extended in the ydirection. The Y-electrodes 313 are disposed at a pitch of 2 mm in thex-axis direction. That is, the pitch between the Y-electrodes 313 is 2mm.

The X-electrodes 312 and the Y-electrodes 313 are formed in such amanner that the connection parts of the rhombic electrodes overlap witheach other via the insulating film on a plan view. Further, the mainparts of the rhombic parts of the X-electrodes 312 and those of theY-electrodes 313 are formed not to overlap with each other. That is, themain part of the rhombic part of the X-electrode and that of theY-electrode are neighboring to each other on a plan view.

FIGS. 20A and 20B show enlarged explanatory charts of the structures ofthe connection parts of the X-electrode and the connection parts of theY-electrode shown in FIG. 19. FIG. 20A is a plan view showing theconnection part between the electrodes shown as a block A in FIG. 19,and FIG. 20B is a sectional view taken along a line A-A′ of FIG. 20A.

The X-electrodes 312 are formed by mutually connecting rhombicelectrodes on a straight line form via a bridge electrode 321. Further,the Y-electrodes 313 are also formed by mutually connecting rhombicelectrodes on a straight line form via a connection part 322 that isformed with identical material. The bridge electrode 321 and theconnection part 322 are insulated by an insulating film 323.

The sectional view structure of the connection part of the X-electrode312 and the Y-electrode 313 as well as the manufacturing procedure willbe described by referring to FIG. 20B. First, the bridge electrode 321is formed by a transparent conductive film such as ITO (indium tinoxide) on the supporting substrate 311 that is a glass substrate.

Then, the insulating film 323 is formed with an organic material on thebridge electrode 321. Through forming it with an organic material, thefilm thickness of the insulating film 323 can be easily formed thick,and an originally unnecessary coupling capacitance formed in theintersection part between the X-electrode 312 and the Y-electrode 313can be made small. The insulating film 323 is formed to cover the bridgeelectrode to insulate the connection part of the Y-electrode 313 and thebridge electrode 321 and not to cover the bridge electrode so that thebridge electrode 321 and the rhombic part of the X-electrode 312 come incontact with each other.

Then, the X-electrodes 312, the Y-electrode 313, the connection parts322, other wirings, and terminals 317 are formed collectively by atransparent conductive film. At last, an insulating film 324 isdeposited by an organic material, and a contact hole is formed in theterminals 317.

A plurality of terminals 317 formed in the supporting substrate 311 areconnected to the X-electrodes 312 or the Y-electrodes 313 via thewirings. One end of a flexible printed circuit (FPC) is laminated to theterminals 317 via an anisotropic conductive film (ACF), and the otherend of FPC is connected to the printed circuit board on which theX-electrode driving circuit 314 and the Y-electrode driving circuit 315are mounted.

Through the steps described above, the tactile sense presentation device310 in the structure shown in FIG. 19 and FIG. 20A can be formed.

The present invention provides the tactile sense presentation devicewhich presents a tactile sense by a beat phenomenon generated byapplying voltage signals of different frequencies from each other to theX-electrodes and the Y-electrodes. Thus, both of the static electricforce between a finger of the user and the X-electrodes and the staticelectric force between the finger and the Y-electrodes need to work onthe finger.

That is, when the X-electrodes 312 and the Y-electrodes 313 overlap witheach other on a plan view, the electric field generated in one of theelectrodes is shielded in the other electrode. Thus, it is better tosuppress the overlap part between the electrodes to be small as much aspossible, so that it is desired to form the X-electrodes 312 and theY-electrodes 313 to be neighboring to each other and to narrow the spacebetween the neighboring electrodes as much as possible.

The shape shown in FIG. 19 is an example of the shapes that can satisfysuch condition. Through forming the X-electrodes 312 and theY-electrodes 313 in such form, it is possible to reduce the overlappingpart between the electrodes and to narrow the gap between theneighboring electrodes for presenting a tactile sense by allowing thestatic electric force to work on the finger efficiently.

The inventors of the present invention have verified by experiments thata tactile sense can be presented to the thenar but cannot be presentedto the fingertip when the pitch of the electrodes is larger than 5 mm.The pitch of the X-electrodes 312 is set as 2 mm and the pitch of theY-electrodes 313 is set as 2 mm in the exemplary embodiment, so that atactile sense can be presented to the fingertip.

Further, the area of the part where the X-electrode 312 and theY-electrode 313 overlap with each other is small, so that the loadcapacity when an alternate current voltage signal is applied to eachelectrode is small. Thus, it is possible to increase the scale of thetactile sense presentation device and to improve the spatial resolutionof the tactile sense presentation device, so that induction ofunnecessary voltages that may be caused by the capacitance coupling ofthe electrodes can be suppressed.

Further, in the shape shown in FIG. 19, a plurality of rhombicelectrodes are provided over the supporting substrate. Thus, when anoriginally unnecessary pattern generated due to the shape of theelectrodes is recognized by human beings, the boundary parts between therhombic part of the X-electrodes 312 and the rhombic part of theY-electrodes 313 is recognized as “oblique straight lines” over theentire surface of the tactile sense presentation device 310. In thisregards, in the exemplary embodiment, the gap between the electrodesshown in FIG. 20A is set as about several μm to several tens of μm, sothat there is almost no possibility that the boundary part is recognizedby human beings. That is, the exemplary embodiment also can provide aneffect of suppressing deterioration of the display quality of thedisplay device even when the tactile sense presentation device 310 isused by being superimposed on the display device.

First Exemplary Embodiment Other structures of Electrodes

Note here that the structures of the X-electrodes 312 and theY-electrodes 313 are not limited to those described in FIGS. 19 and 20.Hereinafter, other structures of the electrodes will be described.

For example, a following structure can be considered. That is, theX-electrodes are formed on a first supporting substrate by connectingrhombic electrodes via a connection part that is formed integrally withidentical material as that of the rhombic electrodes. Similarly, theY-electrodes are formed on a second supporting substrate by connectingrhombic electrodes via a connection part that is formed integrally withidentical material as that of the rhombic electrodes. Then, the firstsupporting substrate and the second supporting substrate are laminatedby using an optical adhesive agent, an optical adhesive sheet, or thelike to form the tactile sense presentation device 310.

In that case, the surface on which the electrodes are formed may belaminated with each other by an optical adhesive agent or the like orthe surfaces where the electrodes are not formed may be laminated witheach other. Also, the surfaces where the electrodes are formed and thesurfaces where the electrodes are not formed may be laminated with eachother. In any of those structures, the X-electrodes and the Y-electrodesintersect with each other via the insulating film. In the case wheresurface on which the electrodes are formed are laminated with eachother, an adhesive agent layer such as the optical adhesive agent or anorganic film or an inorganic film formed on the electrodes after each ofthe electrodes are formed can be used as the insulating film. In thecase where the surfaces where the electrodes are not formed arelaminated with each other, the supporting substrate can be used as theinsulating film.

First Exemplary Embodiment X-Electrode/Y-Electrode Driving Circuit

FIG. 21 is an explanatory chart showing a more detailed structure of theX-electrode driving circuit 314 of the tactile sense presentation device310 shown in FIG. 18. The Y-electrode driving circuit 315 also has thesame structure as that of the X-electrode driving circuit 314, so thatonly the structure of the X-electrode driving circuit 314 will bedescribed herein.

The X-electrode driving circuit 314 includes a data input terminal 331,a clock input terminal 332, and a start pulse input terminal 333 asinput terminals. Those input terminals are connected to the control unit316, and receive control signals generated by the control unit 316.

As output terminals, the X-electrode driving circuit 314 includes aplurality of output terminals 334 which output voltage signals appliedto the X-electrodes 312. In a case shown in FIG. 21, there are fiftyoutput terminals 334, and those are referred to as A₀ to A₄₉,respectively.

Further, in addition to those input/output terminals, the X-electrodedriving circuit 314 includes: an alternate current voltage generatingunit 341 which generates an alternate current voltage of the frequencyf₁; an alternate current voltage generating unit 342 which generates analternate current voltage of the frequency f₂; and an alternate currentvoltage generating unit 343 which generates an alternate current voltageof the frequency f₅. The frequencies f₁, f₂, and f₅ are 1000 Hz, 1240Hz, and 3000 Hz, respectively.

Further, the X-electrode driving circuit 314 includes a 50-bit shiftregister 344. The shift register 344 has fifty output terminals (Q₀ toQ₄₉), and each of those outputs is connected to a 2-bit data register345. Each of the 2-bit data registers 345 is connected to the data inputterminal 331 via a bus.

The output signals from each of the 2-bit data registers 345 areconnected to a 2-input/4-output decoder 346. The 2-input/4-outputdecoder 346 takes the inputted 2-bit signal as an input, and outputs ahigh-level voltage signal to one of the four output terminals accordingto the inputted signal. There is one-on-one relation between theinputted 2-bit signal and the output terminal to which the high-levelsignal is outputted.

One of the output terminals from the 2-input/4-output decoder 346 is notused in the exemplary embodiment, and a gate electrode of a switchtransistor 347 is connected to each of the remaining three outputterminals. The switch transistors 347 connected to each of the threeoutput terminals are referred to as SW1 to SW3.

The terminals on the output side of the switch transistors 347 areconnected in common and connected as inputs of an amplifier 348. Theterminals on the input side of SW1 to SW3 of the switch transistors 347are connected to the output terminals of each of the alternate currentvoltage generating units 341 to 343. That is, alternate current voltagesof each of the frequencies f₁, f₂, and f₅ are inputted to the terminalson the input sides of each of SW1 to SW3. The 2-input/4-output decoder346 executes a function of selectively switching the alternate currentvoltage outputted to the amplifier 348 among those frequencies accordingto the output from the 2-bit data register 345.

Then, the alternate current voltage amplified by the amplifier 348 isoutputted to each of the X-electrodes 312 from the output terminals 334described above. That is, the X-electrode driving circuit 314 functionsas a circuit which selects the alternate current voltage signal of thefrequency f₁, f₂, or f₅ and outputs to the X-electrodes via the outputterminals 334 according to the signal inputted via the data inputterminal 331 from the control unit 316.

FIG. 22 is a time chart showing actions of the X-electrode drivingcircuit 314 shown in FIG. 21. “CLK” is a clock waveform voltage inputtedfrom the control unit 316 via the clock input terminal 332. “D[1: 0]” isa 2-bit data signal inputted from the control unit 316 via the datainput terminal 331. “ST” is a start pulse waveform voltage inputted fromthe control unit 316 via the start pulse input terminals 333.

“D[1: 0]” inputted from the control unit 316 via the data input terminal331 is expressed with a binary number, so that it can take four kinds ofvalues “00”, “01”, “10”, and “11”.

The structure and the actions of the shift register 344 are widely knownin general, so that detailed explanations are omitted. The shiftregister 344 latches the value of ST for every rise edge of CLK, andoutputs it to the output terminal Q₀ of the shift register. The value ofthe output terminal Q₀ is outputted to Q₁ with a delay of one period ofCLK. The value of the output terminal Q₁ is outputted to Q₂ with a delayof one period of CLK. In this manner, the shift register 344 outputs thepulse waveform voltage synchronized with the rise edge of CLK in orderto the output terminals Q₀ to Q₄₉.

When the pulse waveform voltage is outputted to the output terminal ofthe shift register 344, the register value of the 2-bit register 345 isupdated to the value of the data D[1: 0] of that time by synchronizingwith the rise edge, and outputted to the output terminal of the 2-bitdata register 345.

Upon receiving the signal outputted to the terminal of the 2-bit dataregister 345, the 2-input/4-output decoder 346 turns on one of theswitch transistor 347 out of SW1 to SW3. Accordingly, the alternatecurrent voltage signal of the frequency f₁, f₂, or f₅ is outputted tothe output terminal 334.

The X-electrode driving circuit 314 corresponds the frequency f₁ to thedata D[1: 0]=00, the frequency f₂ to the data D[1: 0]=01, and thefrequency f₅ to the data D[1: 0]=10. Thus, the voltage signal whosefrequency is f₅ is outputted to A₀ of the output terminal 334 at thetime 1 shown in FIG. 22, the voltage signal whose frequency is f₂ isoutputted to A₁ of the output terminal 334 at the time 2, and thevoltage signal whose frequency is f₁ is outputted to A₂ of the outputterminal 334 at the time 3. The amplitude of each of the voltage signalsis 70 V. Note here that D[1: 0]=11 is not used herein.

The frequency of the voltage signal outputted to the output terminal 334does not change until the pulse waveform voltage is inputted next to thestart pulse input terminal 333 and the register value of the 2-bit dataregister 345 is updated.

FIG. 22 shows Q₀ to Q₂ out of the output waveforms of fifty outputterminals Q₀ to Q₄₉ of the shift register 344, and other outputwaveforms are not shown. Similarly, regarding the voltage signals, A₀ toA₂ out of the fifty output terminals 344 A₀ to A₄₉ of the X-electrodedriving circuit 314, and other voltage signals are not shown.

The tactile sense presentation device 310 is constituted by formingtwenty-eight X-electrodes 312 and forty-six Y-electrodes 313 on thesupporting substrate 311. Regarding the X-electrode driving circuit 314,twenty-eight output terminals A₀ to A₂₇ out of the fifty outputterminals 334 shown in FIG. 21 are connected electrically to each of theX-electrodes 312. Regarding the Y-electrode driving circuit 315,forty-six output terminals A₀ to A₄₅ out of the fifty output terminals334 shown in FIG. 21 are connected electrically to each of theY-electrodes 313.

The control unit 316 is constituted with a logic circuit, and outputsthe control signal shown in FIG. 22 to the X-electrode driving circuit314 and the Y-electrode driving circuit 315. This action can be achievedby a known technique, so that the detailed structure of the control unit316 is not specifically described and it is not included in a scope ofthe appended claims of the present invention.

The X-electrode driving circuit 314 (the Y-electrode driving circuit315) shown in FIG. 21 is intended to be used in the second basicembodiment described above. However, those can be also used in the firstbasic embodiment when the alternate current voltage generating unit 343of the frequency f₅ is omitted. Further, by employing a structure inwhich four switch transistors are provided to one output terminal andone out of the four frequencies f₁ to f₄ is selected and outputtedaccording to the value of D[1: 0], those can be used also with the thirdbasic embodiment.

With the first exemplary embodiment described above, it is possible toachieve an effect of presenting a sense of texture more strongly inaddition to the effect acquired by each of the above-described basicembodiments.

The reason thereof is that more regions where a beat phenomenon occursstrongly are provided by employing the form in which: on a plan view,the X-electrodes are formed by coupling a plurality of rhombicelectrodes in a form like a string of beads via a connection parts; theY-electrodes are formed by coupling a plurality of rhombic electrodes ina form like a string of beads via a connection parts; the X-electrodesand the Y-electrodes overlap with each other at the connection parts;and the main parts of the rhombic parts of the X-electrodes and theY-electrodes are neighboring to each other.

Further, it is also because the pitch between the X-electrodes andbetween the Y-electrodes is set to be smaller than 5 mm so as toefficiently stimulate Pacinian corpuscle that is one of the skinmechanoreceptors of human beings.

Further, it is also because such structure that makes it possible tosatisfy conflicting demands for reducing the parasitic capacitance ofthe electrodes and reducing the gap between the X-electrodes and theY-electrodes and to give a strong stimulation to the skinmechanoreceptor is achieved by forming the X-electrodes constituted bycoupling a plurality of rhombic electrodes in a form like a string ofbeads via the connection parts and the Y-electrodes constituted bycoupling a plurality of rhombic electrodes in a form like a string ofbeads via the connection points to have the equivalent pitches betweenthe rhombic parts on the substrate.

As described above, the present invention is designed as the structurein which: each of the voltage signals of the first and secondfrequencies is applied to the X-electrodes and the Y-electrodesinsulated from each other; and electric beat oscillation is generated inthe target region by an absolute value of the difference between thefirst and second frequencies. Therefore, physical beat oscillation canbe given to the finger of the user effectively, and the beat oscillationis not given to a part that is irrelevant to the target region.

As an exemplary advantage according to the invention, this makes itpossible to provide the tactile sense presentation device, theelectronic apparatus, and the tactile sense presentation method, whichexhibit an excellent characteristic of making it possible to executeoperations only by a tactile sense without looking at the hands byeffectively presenting a tactile sense (a sense of texture) on the touchpanel.

Second Exemplary Embodiment Supporting Substrate and Electrodes

In addition to the structures of the first to fifth basic embodiments ofthe present invention, a second exemplary embodiment of the presentinvention is designed is such a manner that, on a plan view: theX-electrodes and the Y-electrodes are both formed by coupling aplurality of specific shape electrodes in a form like a string of beadsvia connection parts, the X-electrodes and the Y-electrodes overlap witheach other in the connection parts, and the specific shape parts of theX-electrodes and the Y-electrodes are neighboring to each other; and thespecific shape part of the X-electrodes, or, the Y-electrodes intersectswith a first straight line which connects a first intersection part anda second intersection part among the intersection parts of arbitraryX-electrodes and arbitrary Y-electrodes described above and is not inparallel to the first and second directions or a second straight linewhich connects the first intersection part and a third intersection partamong the arbitrary X-electrodes and the arbitrary Y-electrodes and isnot in parallel to the first and second directions.

Not only making it possible to acquire the same effects as those of thefirst to fifth basic embodiments, this structure also makes it possibleto present a sense of texture more strongly by transmitting stillstronger beat generated between the X-electrodes and the Y-electrodes tothe finger of the user.

This will be described in more details hereinafter.

FIG. 23 is an explanatory chart showing the structure of a tactile sensepresentation device 410 according to the second exemplary embodiment ofthe present invention. In the tactile sense presentation device 410, aplurality of X-electrodes 412 extended in the x direction on a planartype supporting substrate 311 same as that of the first exemplaryembodiment and a plurality of Y-electrodes 413 extended in the ydirection orthogonal to the X-electrodes 412 on the supporting substrate311 are formed.

The X-electrodes 412 and the Y-electrodes 413 intersect with each otherin the intersection parts thereof via an insulating film, and electricinsulation between the both is maintained. Further, an insulating filmis formed on the X-electrodes 412 and the Y-electrodes 413 forelectrically insulating between the X-electrodes 412 and a finger andbetween the Y-electrodes 413 and a finger when a user touches thedisplay surface of the tactile sense presentation device 410 by thefinger from the above.

An X-electrode driving circuit 314 same as that of the first exemplaryembodiment is connected to each of the X-electrodes 412, and aY-electrode driving circuit 315 same as that of the first exemplaryembodiment is connected to each of the Y-electrodes 313. The X-electrodedriving circuit 314 and the Y-electrode driving circuit 315 areconnected to a control unit 316 same as that of the first exemplaryembodiment. Explanations of the X-electrode driving circuit 314, theY-electrode driving circuit 315, and the control unit 316 are omittedherein.

FIG. 24 is a plan view showing specific shapes of the X-electrodedriving circuit 412 and the Y-electrode driving circuit 413 shown inFIG. 23. In FIG. 24, the X-electrodes 412 are shown with dotted lines,and the Y-electrodes 413 are shown with solid lines, respectively.

The X-electrodes 412 are formed by coupling a plurality of prescribedshape electrodes via connection parts which are the bridge electrodes421 in a form like a string of beads. The Y-electrodes 413 are formed bycoupling a plurality of prescribed shape electrodes in a form like astring of beads via connection parts formed integrally by identicalmaterial as that of the Y-electrodes.

“Prescribed shape” herein is a shape in which the boundary part betweenthe rhombic part of the X-electrode 412 and the rhombic part of theY-electrode 413 neighboring to each other is changed to enter the insideof one of the rhombic shapes while taking the rhombic shape of the firstexemplary embodiment described above as the base. The boundary partherein can also be referred to as a gap 422 with a prescribed width.

In the first exemplary embodiment, the boundary part between the rhombicelectrode contained in the X-electrode 312 and the rhombic electrodecontained in the Y-electrode 313 can be considered to exist at aposition on a straight line that connects the intersection parts of theneighboring X-electrodes and Y-electrodes in a direction different fromboth the X direction and the Y direction, i.e., at a position on astraight line that connects neighboring intersection parts almostobliquely at 45-degree direction or −45-degree direction. Meanwhile, itis the feature of the second exemplary embodiment that the boundary partbetween the X-electrodes 412 and the Y-electrodes 413 is away from theposition on the straight line in the obliquely 45-degree direction or−45-degree direction.

The tactile sense presentation device according to the present inventionpresents a tactile sense by a beat phenomenon generated by the voltagesignal applied to the X-electrodes and the voltage signal applied to theY-electrodes. Thus, the beat phenomenon appears strongly in the boundaryparts between the X-electrodes and the Y-electrodes, so that it isdesired to have many boundary parts in the region where the human bodysuch as a fingertip and the tactile sense presentation device come incontact. That is, it is desirable to have long boundary lines for makingit possible to present a stronger tactile sense.

Therefore, the second exemplary embodiment in which the boundary partbetween the rhombic part of the X-electrode 412 and the rhombic part ofthe Y-electrode 413 neighboring to each other enters inside of one ofthe rhombic parts exhibits such an effect that a stronger tactile sensecan be presented compared to the case of the first exemplary embodiment.

Further, regarding the electrode shapes of the exemplary embodiment, theboundary part entered inside one of the rhombic parts does not exist onthe straight line connecting between the neighboring connection parts ofthe X-electrodes 412 and the straight line connecting between theneighboring connection parts of the Y-electrodes 413. Since theelectrodes are in such shape, it is possible to suppress increase in theresistance value between both ends of the X-electrodes and theresistance value between both ends of the Y-electrodes even in the casewhere the boundary part between the rhombic part of the X-electrode 12and the rhombic part of the Y-electrode 413 neighboring to each other isformed to enter the inside of one of the rhombic parts.

Thereby, it is possible to suppress increase each time constant of theX-electrodes 412 and the Y-electrodes 413. This makes it possible toincrease the dimension of the display surface of the tactile sensepresentation device and to use voltage signals of still higherfrequencies.

FIG. 25 is a plan view showing the specific shapes of the X-electrode412 and the Y-electrode 413 shown in FIG. 23 in a different viewpointfrom that of FIG. 24. In FIG. 25, the X-electrode 412 is shown withdotted lines and the Y-electrode 413 is shown with solid lines as in thecase of FIG. 24.

The X-electrode 412 is formed by coupling a plurality of polygonalelectrodes having twenty vertexes in a form like a string of beads viaconnection parts. There is one vertex in a part where the polygon comesin contact with the connection part, and the polygons are coupled via abridge electrode 421. The Y-electrode 413 is formed by coupling aplurality of polygonal electrodes having twenty vertexes in a form likea string of beads via connection parts 423. The connection part 423 isformed integrally by identical material as that of the polygonalelectrodes of the Y-electrodes 413.

The intersection part between the X-electrode 412 and the Y-electrode413 is a logical product part of the figures of the bridge electrode 421and the connection part 423. Nine pieces of such intersection parts areincluded in FIG. 25. Among those, the intersection part in the center ofthe drawing is shown as P. In the periphery of the intersection part P,there are eight intersection parts neighboring to P.

Considering straight lines passing through the intersection part P andone intersection part among the eight intersection parts neighboring tothe intersection part P, there are two straight lines that are not inparallel to a first direction (x direction of an orthogonal coordinatesystem shown in the drawing) and in a second direction (y direction).Those are shown as straight lines m and n in FIG. 25. The straight linem passes through the intersection part P and the intersection part Qthat is neighboring to the intersection part P in 45-degree directionfrom the intersection part P. The straight line n passes through theintersection part P and the intersection part Q that is neighboring tothe intersection part P in 135-degree direction from the intersectionpart P.

At this time, the main part of the polygon of the X-electrode 412 or themain part of the polygon of the Y-electrode 413 intersects with thestraight line m or the straight line n. For example, when moving towardsthe intersection part Q from the intersection part P on the straightline m, the main part of the polygon electrode constituting theY-electrode 413 intersects with the straight line m. An arrow and asymbol l are shown in that part. Further, when moving towards theintersection part R from the intersection part P on the straight line n,the main part of the polygon electrode constituting the X-electrode 412intersects with the straight line n. An arrow and a symbol II are shownin that part.

As described, it is the feature of this exemplary embodiment that themain part of the polygonal electrode constituting the X-electrode 412 orthe main part of the polygonal electrode constituting the Y-electrode413 intersects with the straight line m or the straight line n. Withsuch feature, the boundary line between the X-electrodes 412 and theY-electrodes 413 can be formed longer than the case of the firstexemplary embodiment, so that a stronger tactile sense can be presented.

With the second exemplary embodiment described above, it is possible toachieve an effect of presenting a sense of texture more strongly inaddition to the effect acquired by the first exemplary embodimentdescribed above.

The reason is that, on a plan view, the exemplary embodiment employs theelectrode shape in which the prescribed shape main part of theX-electrode or the Y-electrode intersects with the straight line m orthe straight line n provided that the intersection part between anarbitrary X-electrode and an arbitrary Y-electrode in the center of thetactile sense presentation device is P, and the straight lines that arenot in parallel to the first direction and the second direction amongthe straight lines passing through one of the intersections out of theintersection part P and the eight intersection parts neighboring to theintersection part P are the straight lines m and n.

This makes it possible to extend the boundary lines between theX-electrodes and the Y-electrodes longer and to stimulate more Paciniancorpuscles on the skin of the operator as a result. At the same time, itis also because increase in the resistance values of the electrodes issuppressed, increase in the time constant of the electrodes issuppressed, and deterioration in the voltages generated in theelectrodes is suppressed by employing the electrode shape in which theboundary lines between the X-electrodes and the Y-electrodes do notexist on the straight line connecting between the intersection partsincluded in a single X-electrode or the straight line connecting betweenthe intersection parts included in a single Y-electrode.

Third Exemplary Embodiment Supporting Substrate and Electrodes

In addition to the structures of the first to fifth basic embodimentsand the second exemplary embodiment of the present invention, a thirdexemplary embodiment of the present invention is designed is such amanner that, on a plan view: the X-electrodes are formed on the firstsupporting substrate by connecting the plurality of electrodes viaconnection parts formed integrally with identical material as a materialof the plurality of electrodes; the Y-electrodes are formed on thesecond supporting substrate by connecting the plurality of electrodesvia connection parts formed integrally with identical material as amaterial of the plurality of electrodes; and the first and secondsupporting substrates are adhered to each other by sandwiching aninsulating film.

With this structure, it is also possible to increase the scale of thetactile sense presentation device and to improve the spatial resolutionin addition to achieving the same effects as those of the first to fifthbasic embodiments and the first and second exemplary embodiments of thepresent invention.

This will be described in more details hereinafter.

FIG. 26 is an explanatory chart showing the structure of a tactile sensepresentation device 510 according to the third exemplary embodiment ofthe present invention. A plurality of X-electrodes 512 extended in the xdirection on a plan type supporting substrate 511 and a plurality ofY-electrodes 513 extended in the y direction orthogonal to theX-electrodes 512 on the supporting substrate 511 are formed.

The X-electrodes 512 and the Y-electrodes 513 intersect with each otherin the intersection parts thereof via an insulating film, and electricinsulation between the both is maintained. Further, an insulating filmis formed on the X-electrodes 512 and the Y-electrodes 513 forelectrically insulating between the X-electrodes 512 and a finger andbetween the Y-electrodes 513 and a finger when a user touches thedisplay surface of the tactile sense presentation device 510 by thefinger from the above.

An X-electrode driving circuit 314 same as that of the first exemplaryembodiment is connected to each of the X-electrodes 512, and aY-electrode driving circuit 315 same as that of the first exemplaryembodiment is connected to each of the Y-electrodes 513. The X-electrodedriving circuit 314 and the Y-electrode driving circuit 315 areconnected to a control unit 316 same as that of the first exemplaryembodiment. Explanations of the X-electrode driving circuit 314, theY-electrode driving circuit 315, and the control unit 316 are omittedherein.

Regarding the shape of the X-electrode 512 and the Y-electrode 513 on aplan view, a plurality of rhombic electrodes are coupled in a form likea string of beads to be connected electrically and extended in the xdirection or the y direction as in the case of the first exemplaryembodiment shown in FIG. 19. Alternatively, it may be changed to theshape in which the boundary part between the rhombic part of theX-electrode and the rhombic part of the Y-electrode neighboring to eachother enters inside one of the rhombic parts as in the case of thesecond exemplary embodiment.

The difference between the third exemplary embodiment and the first tosecond exemplary embodiments is its sectional structure andmanufacturing method. Those will be described hereinafter. FIGS. 27A and27B are enlarged explanatory charts showing the structure of theconnection part between the X-electrode 512 and the Y-electrode 513 ofthe tactile sense presentation device 510 shown in FIG. 26. FIG. 27A isa plan view showing the connection part between the X-electrode 512 andthe Y-electrode 513, and FIG. 27B is a sectional view taken along a lineB-B′ of FIG. 27A.

In this exemplary embodiment, the supporting substrate 511 is dividedinto first and second supporting substrates 511 a and 511 b. First, theX-electrode 512 constituted by connecting the rhombic electrodes with aconnection part formed integrally by using identical material as that ofthe electrodes is formed on the first supporting substrate 511 a. Then,the Y-electrode 513 constituted by connecting the rhombic electrodeswith a connection part formed integrally by using identical material asthat of the electrodes is formed on the second supporting substrate 511b. Thereafter, the first and second supporting substrates 511 a and 511b are adhered by sandwiching an insulating film 521 to form the tactilesense presentation device 510.

For the insulating film 521, an insulating optical adhesive agent can beused. This includes a function which adhesively laminates the first andsecond supporting substrates 511 a and 511 b, and a function whichmutually insulates the X-electrode 512 and the Y-electrode 513.

As shown in FIG. 27A, the X-electrode 512 is formed by connecting therhombic electrodes by the connection part formed integrally by usingidentical material as that of the electrode. Similarly, the Y-electrode513 is formed by connecting the rhombic electrodes by the connectionpart formed integrally by using identical material as that of theelectrode. In the tactile sense presentation device on a plan view, theX-electrode 512 and the Y-electrode 513 overlap with each other in theconnection part, and the main parts of the rhombic parts of theX-electrode 512 and the Y-electrode 513 are neighboring to each other.

The sectional structure and the manufacturing steps of the tactile sensepresentation device 510 will be described by using FIG. 27B. The firstand second supporting substrates 511 a and 511 b are both glasssubstrates. First, the X-electrodes 512 are formed by ITO on the firstsupporting substrate 511 a. At that time, wirings and terminals same asthose shown in FIG. 19 are formed simultaneously by ITO.

Then, the Y-electrodes 513 are formed by ITO on the second supportingsubstrate 511 b. At that time, wirings and terminals same as those shownin FIG. 19 are formed simultaneously by ITO. Subsequently, a flexibleprinted circuit is laminated to the terminals formed on the first andsecond supporting substrates 511 a and 511 b. Then, the surface wherethe X-electrodes 512 are formed and the surface where the Y-electrodes513 are formed on the first and second supporting substrates 511 a and511 b are laminated by using an optical adhesive agent. The X-electrodes512 and the Y-electrodes 513 intersect with each other via the opticaladhesive agent that functions as the insulating film 521.

Through employing the sectional structure, it becomes unnecessary toplace the bridge electrodes. That is, minute patterning processing ofthe insulating film 521 becomes unnecessary, so that the thickness ofthe insulating film 521 can be made thicker easily within a range ofseveral μm to several mm. As a result, the static capacity of theparallel flat plate capacitor formed in the intersection parts betweenthe X-electrode 512 and the Y-electrode 513 overlap with each other canbe made small, so that the load capacity of each of the electrodes canbe made small. Therefore, the driving frequencies of the electrodes canbe increased still more. This means to be able to increase the scale ofthe tactile sense presentation device or to improve the spatialresolution of the tactile sense presentation device.

Fourth Exemplary Embodiment Supporting Substrate and Electrodes

In addition to the structures of the first to fifth basic embodimentsand the second exemplary embodiment of the present invention, a fourthexemplary embodiment of the present invention is designed in such amanner that, on a plan view: the X-electrodes are formed on thesupporting substrate by connecting the plurality of electrodes viaconnection parts formed integrally with identical material as a materialof the plurality of electrodes; and the Y-electrodes are formed on thesecond supporting substrate by connecting the plurality of electrodesvia connection parts formed integrally with identical material as amaterial of the plurality of electrodes by sandwiching an insulatingfilm between with the X-electrodes.

With this structure, it is also possible to increase the scale of thetactile sense presentation device, to improve the spatial resolution,and to omit minute patterning processing in addition to achieving thesame effects as those of the first to fifth basic embodiments and thefirst and second exemplary embodiments of the present invention.

This will be described in more details hereinafter.

FIG. 28 is an explanatory chart showing the structure of a tactile sensepresentation device 560 according to the fourth exemplary embodiment ofthe present invention. A plurality of X-electrodes 562 extended in the xdirection on a plan type supporting substrate 561 and a plurality ofY-electrodes 563 extended in the y direction orthogonal to theX-electrodes 562 on the supporting substrate 561 are formed.

An X-electrode driving circuit 314 same as that of the first exemplaryembodiment is connected to each of the X-electrodes 562, and aY-electrode driving circuit 315 same as that of the first exemplaryembodiment is connected to each of the Y-electrodes 563. The X-electrodedriving circuit 314 and the Y-electrode driving circuit 315 areconnected to a control unit 316 same as that of the first exemplaryembodiment. Explanations of the X-electrode driving circuit 314, theY-electrode driving circuit 315, and the control unit 316 are omittedherein.

The difference between the fourth exemplary embodiment and the first tothird exemplary embodiments is its sectional structure and manufacturingmethod. Those will be described hereinafter. FIGS. 29A and 29B areenlarged explanatory charts showing the structure of the connection partbetween the X-electrode 562 and the Y-electrode 563 of the tactile sensepresentation device 560 shown in FIG. 28. FIG. 29A is a plan viewshowing the connection part between the X-electrode 562 and theY-electrode 563, and FIG. 29B is a sectional view taken along a lineC-C′ of FIG. 29A.

As shown in FIG. 29A, the X-electrode 562 is formed by connecting therhombic electrodes by the connection part formed integrally by usingidentical material as that of the electrode as in the case of the thirdexemplary embodiment. Similarly, the Y-electrode 563 is formed byconnecting the rhombic electrodes by the connection part formedintegrally by using identical material as that of the electrode. In thetactile sense presentation device on a plan view, the X-electrode 562and the Y-electrode 563 overlap with each other in the connection part,and the main parts of the rhombic parts of the X-electrode 562 and theY-electrode 563 are neighboring to each other.

Regarding the sectional structure of the tactile sense presentationdevice 560, as shown in FIG. 29B, the tactile sense presentation deviceaccording to this exemplary embodiment is formed by stacking theX-electrodes 562, an insulating film 571, the Y-electrodes 563, and aninsulating film 572 in order on the supporting substrate 561. That is,the bridge electrodes are unnecessary with this exemplary embodiment.

Because the bridge electrodes are unnecessary, minute patterningprocessing of the insulating film 571 is not required. Thus, thethickness of the insulating film 571 can be made thicker easily within arange of several μm to several mm. As a result, the static capacity ofthe parallel flat plate capacitor formed in the intersection partsbetween the X-electrode 562 and the Y-electrode 563 overlapping witheach other can be made small, so that the load capacity of each of theelectrodes can be made small. Therefore, the driving frequencies of theelectrodes can be increased still more. This means to be able toincrease the scale of the tactile sense presentation device or toimprove the spatial resolution of the tactile sense presentation device.Needless to say, there is also an incidental effect of making itpossible to decrease the processing cost, which is achieved by omittingthe minute patterning processing.

Applied Embodiment

FIG. 30 is an explanatory chart showing the structure of an electronicapparatus 600 according to an applied embodiment of the presentinvention. Specifically, the electronic apparatus 600 is a smartphone, atablet type electronic book reader, a notebook type personal computer,or the like.

The electronic apparatus 600 includes a touch-panel type display device601, and a tactile sense presentation device 610 corresponding to one ofthe first to fifth basic embodiments or the first to fourth exemplaryembodiments described above is provided on the front face or the backface of the touch-panel type display device 601. When astatic-capacitance type touch panel that is currently the mainstream isemployed as the touch-panel type display device 601, the functionthereof and the function of the tactile sense presentation device 610cannot be achieved at the same time. Therefore, it is desirable to usean optical touch panel or the like.

With the electronic apparatus 600, the processing result acquired by abuilt-in processor 603 is displayed on the touch-panel type displaydevice 601, and a user executes an operation input on the touch-paneltype display device 601 according to the display. The electronicapparatus 600 may be of a type which does not include a built-inprocessor, with which the touch-panel type display device 601 displaysprocessing result acquired by an external device (e.g., a desk-top typepersonal computer) and an operation input according to the display isreturned to the external device.

A plurality of operation keys 602 are displayed on the touch-panel typedisplay device 601, and the tactile sense presentation device 610presents a plurality of individual senses of texture at positionscorresponding to each of the operation keys 602 accordingly. The usercan find the positions of the operation keys according to the senses oftexture, so that the user can execute a key input without carefullylooking at the operation keys. Therefore, it is possible to overcome theabove-described issue of “smartphoning while walking” and to overcomesuch issue that visually impaired users cannot use those electronicapparatuses.

Further, as described above, it is practically impossible with thetechnique depicted in Patent Document 1 described above to change thepositions and number of the areas where a sense of texture is to bepresented. Meanwhile, the present invention does not requirerearrangement of the electrodes, and it is possible to flexibly changethe positions and the numbers of the areas where a sense of texture isto be presented by simply changing the numbers of the electrodes towhich the voltage is applied and changing the frequency thereof.

Alternatively, the electronic apparatus 600 can also be used as anavigation device loaded on mobile units such as automobiles, bicycles,two-wheeled vehicles, airplanes, trains, and ships. FIG. 31 is anexplanatory chart showing the structure of a mobile unit 700 accordingto the applied embodiment of the present invention. The mobile unit 700includes: a driver's seat 701 where the user (driver) is seated; adashboard 702 to which the electronic apparatus 600 shown in FIG. 30 isloaded as a navigation device; a steering mechanism 703 such as asteering wheel, an accelerator, and a brake; etc.

As in the case shown in FIG. 30, the electronic apparatus 600 presents aplurality of individual senses of texture at positions that correspondto the operation keys 602. The user can execute operation inputaccording to the senses of texture. Further, it is also possible topresent a sense of texture to a route displayed on a map according tothe route information presented as a result of processing to make thedisplay of the route conspicuous.

With the mobile unit 700, the user can operate the navigation devicewhile concentrating on the execution of fulfilling the obligation ofpaying attention to the road ahead. Therefore, the user can continuesafe driving.

While the present invention has been described by referring to thespecific embodiments shown in the drawings, the present invention is notlimited only to the embodiments shown in the drawings. Any knownstructures can be employed as long as the effects of the presentinvention can be achieved therewith.

The whole or part of the exemplary embodiments disclosed above can bedescribed as, but not limited to, the following Supplementary Notes:

(Supplementary Note 1)

A tactile sense presentation device, including:

a supporting substrate; a plurality of X-electrodes extended in parallelto each other along a first direction on the supporting substrate; aplurality of Y-electrodes extended in parallel to each other along asecond direction on the supporting substrate by being insulated from theX-electrodes; and a driving circuit which applies a first-frequencyvoltage signal to the X-electrode corresponding to information regardinga target region inputted from outside among the plurality ofX-electrodes, and applies a second-frequency voltage signal to theY-electrode corresponding to information regarding the target regioninputted from outside among the plurality of Y-electrodes to generateelectric beat oscillation in the target region by an absolute value of adifference between the first and second frequencies.

(Supplementary Note 2)

A tactile sense presentation device, including:

a supporting substrate; a plurality of X-electrodes extended in parallelto each other along a first direction on the supporting substrate; aplurality of Y-electrodes extended in parallel to each other along asecond direction on the supporting substrate by being insulated from theX-electrodes; and a driving circuit which applies a first-frequencyvoltage signal to the X-electrode corresponding to information regardinga target region inputted from outside among the plurality ofX-electrodes, and applies a second-frequency voltage signal to theY-electrode corresponding to information regarding the target regioninputted from outside among the plurality of Y-electrodes, wherein:

the first and second frequencies are both 500 Hz or more; and

there is a period where an absolute value of a difference between thefirst and second frequencies is larger than 10 Hz and less than 1000 Hz.

(Supplementary Note 3)

The tactile sense presentation device as depicted in Supplementary Note2, wherein

the driving circuit includes a function which grounds an electrode towhich the first-frequency voltage signal is not applied among theplurality of X-electrodes and an electrode to which the second-frequencyvoltage signal is not applied among the plurality of Y-electrodes orapplies a direct current voltage to such electrodes.

(Supplementary Note 4)

The tactile sense presentation device as depicted in Supplementary Note2, wherein

the driving circuit includes a function which applies a third-frequencyvoltage signal to an electrode to which the first-frequency voltagesignal is not applied among the plurality of X-electrodes and to anelectrode to which the second-frequency voltage signal is not appliedamong the plurality of Y-electrodes.

(Supplementary Note 5)

The tactile sense presentation device as depicted in Supplementary Note4, wherein:

the third frequency is between 2.5 Hz and 5 Hz, both inclusive, or 500Hz or more; and

an absolute value of a difference between the third frequency and thefirst frequency and an absolute value of a difference between the thirdfrequency and the second frequency are both 10 Hz or less or 1000 Hz ormore.

(Supplementary Note 6)

The tactile sense presentation device as depicted in Supplementary Note2, wherein

the driving circuit includes a function which applies thefirst-frequency voltage signal to the X-electrodes corresponding to afirst target region while applying the second-frequency voltage signalto the Y-electrodes corresponding to the first target region and, at thesame time, applies a third-frequency voltage signal to the X-electrodescorresponding to a second target region while applying afourth-frequency voltage signal to the Y-electrodes corresponding to thesecond target region.

(Supplementary Note 7)

The tactile sense presentation device as depicted in Supplementary Note6, wherein:

the first to fourth frequencies are all 500 Hz or more;

an absolute value of a difference between the first and secondfrequencies and an absolute value of a difference between the third andfourth frequencies are both larger than 10 Hz and less than 1000 Hz; and

an absolute value of a difference between the first and fourthfrequencies and an absolute value of a difference between the second andthird frequencies are both 10 Hz or less or 1000 Hz or more.

(Supplementary Note 8)

The tactile sense presentation device as depicted in Supplementary Note2, wherein

in a plurality of prescribed target regions, an absolute value of adifference of the frequencies of voltage signals applied by the drivingcircuit to the X-electrodes and the Y-electrodes contained in the targetregions is larger than 10 Hz and less than 1000 Hz; and

in intersection parts excluding the target regions, which are formed bythe X-electrodes or the Y-electrodes constituting the target regions, anabsolute value of a difference in the frequencies of the voltage signalsapplied to the X-electrodes and the Y-electrodes forming theintersection parts is 10 Hz or less or 1000 Hz or more.

(Supplementary Note 9)

The tactile sense presentation device as depicted in Supplementary Note2, wherein:

on a plan view of the supporting substrate, the X-electrodes and theY-electrodes are both formed by coupling a plurality of rhombicelectrodes in a form like a string of beads via connection parts; theX-electrodes and the Y-electrodes overlap with each other in theconnection parts; and the rhombic parts of the X-electrodes and theY-electrodes are neighboring to each other.

(Supplementary Note 10)

The tactile sense presentation device as depicted in Supplementary Note2, wherein:

on a plan view of the supporting substrate, the X-electrodes and theY-electrodes are both formed by coupling a plurality of specific shapeelectrodes in a form like a string of beads via connection parts, theX-electrodes and the Y-electrodes overlap with each other in theconnection parts, and the specific shape parts of the X-electrodes andthe Y-electrodes are neighboring to each other; and

the specific shape part of the X-electrodes or the Y-electrodesintersects with a first straight line which connects a firstintersection part and a second intersection part among the intersectionparts of arbitrary X-electrodes and arbitrary Y-electrodes describedabove and is not in parallel to the first and second directions or asecond straight line which connects the first intersection part and athird intersection part among the intersection parts of arbitraryX-electrodes and arbitrary Y-electrodes and is not in parallel to thefirst and second directions.

(Supplementary Note 11)

The tactile sense presentation device as depicted in Supplementary Note9, wherein:

on a plan view of the supporting substrate, either the X-electrodes orthe Y-electrodes are formed by connecting the plurality of electrodesvia connection parts formed integrally with identical material as amaterial of the plurality of electrodes; and the other ones of theX-electrodes and the Y-electrodes include bridge electrodes whichelectrically connect parts where the plurality of electrodes aredisconnected.

(Supplementary Note 12)

The tactile sense presentation device as depicted in Supplementary Note9 or 10, wherein:

on a plan view of the supporting substrate, the X-electrodes are formedon a first supporting substrate by connecting the plurality ofelectrodes via connection parts formed integrally with identicalmaterial as a material of the plurality of electrodes; the Y-electrodesare formed on a second supporting substrate by connecting the pluralityof electrodes via connection parts formed integrally with identicalmaterial as a material of the plurality of electrodes; and the first andsecond supporting substrates are adhered to each other by sandwiching aninsulating film.

(Supplementary Note 13)

The tactile sense presentation device as depicted in Supplementary Note9 or 10, wherein:

on a plan view of the supporting substrate, the X-electrodes are formedon the supporting substrate by connecting the plurality of electrodesvia connection parts formed integrally with identical material as amaterial of the plurality of electrodes; and the Y-electrodes are formedon the supporting substrate by connecting the plurality of electrodesvia connection parts formed integrally with identical material as amaterial of the plurality of electrodes by sandwiching an insulatingfilm between with the X-electrodes.

(Supplementary Note 14)

The tactile sense presentation device as depicted in Supplementary Note2, wherein

the plurality of X-electrodes are disposed in parallel to each other ata pitch smaller than 5 mm,

the plurality of Y-electrodes are disposed in parallel to each other ata pitch smaller than 5 mm

(Supplementary Note 15)

The tactile sense presentation device as depicted in Supplementary Note2, wherein:

the driving circuit includes a function which applies thefirst-frequency voltage signal of 500 Hz or more to the X-electrodescorresponding to information regarding the target region inputted fromoutside among the plurality of X-electrodes and applies thesecond-frequency voltage signal of 500 Hz or more to the Y-electrodescorresponding to information regarding the target region among theplurality of Y-electrodes; and

changes at least one of the first and second frequencies chronologicallywithin a range that is not lower than 500 Hz.

(Supplementary Note 16)

The tactile sense presentation device as depicted in Supplementary Note15, including:

a first period where an absolute value of a difference between the firstfrequency and the second frequency is larger than 10 Hz and less than1000 Hz; and

a second period where an absolute value of a difference between thefirst frequency and the second frequency is 10 Hz or less or 1000 Hz ormore.

(Supplementary Note 17)

The tactile sense presentation device as depicted in Supplementary Note16, wherein

the first period and the second period are set alternately.

(Supplementary Note 18)

The tactile sense presentation device as depicted in Supplementary Note15, wherein

the driving circuit continuously changes at least one of the first andsecond frequencies in a range that is not lower than 500 Hz according totime.

(Supplementary Note 19)

An electronic apparatus, including:

a touch-panel type display device which displays a processing resultexecuted by a processor provided therein and accepts an operation inputwhich corresponds to the processing result; and

the tactile sense presentation device as depicted in any one ofSupplementary Notes 1 to 14, which presents a sense of texturecorresponding to the display of the processing result.

(Supplementary Note 20)

A mobile unit, including the electronic apparatus as depicted inSupplementary Note 19 loaded as an on-vehicle device.

(Supplementary Note 21)

A tactile sense presentation method used with a tactile sensepresentation device which includes: a supporting substrate; a pluralityof X-electrodes extended in parallel to each other along a firstdirection on the supporting substrate; and a plurality of Y-electrodesextended in parallel to each other along a second direction on thesupporting substrate by being insulated from the X-electrodes, wherein:

a control unit gives information regarding a target region inputted fromoutside to a driving circuit; and

the driving circuit applies a first-frequency voltage signal to theX-electrodes corresponding to the target region; and applies asecond-frequency voltage signal to the Y-electrodes corresponding to thetarget region to generate electric beat oscillation in the target regionby an absolute value of a difference between the first and secondfrequencies.

INDUSTRIAL APPLICABILITY

The present invention can be utilized in various kinds of apparatuses ofthe fields where the display devices such as liquid crystals are used.Particularly, the present invention is suited for being used in theapparatuses that includes a touch-panel type display device. Morespecifically, typical apparatuses are smartphones, tablet terminals,note-type personal computers, and the like as described above. Otherthan those, the present invention can also be applied to game machines,music players, car navigation devices, and the like.

The present invention is suited for use for overcoming the issue of“executing operations while walking” when using those apparatuses, forimplementing barrier-free use (enabling visually impaired users to usethose electronic apparatuses), improving the operability throughpresenting a tactile sense according to the displayed content, and thelike.

What is claimed is:
 1. A tactile sense presentation device, comprising:a supporting substrate; a plurality of X-electrodes extended in parallelto each other along a first direction on the supporting substrate; aplurality of Y-electrodes extended in parallel to each other along asecond direction on the supporting substrate by being insulated from theX-electrodes; and a driving circuit which applies a first-frequencyvoltage signal to the X-electrode corresponding to information regardinga target region inputted from outside among the plurality ofX-electrodes, and applies a second-frequency voltage signal to theY-electrode corresponding to information regarding the target regioninputted from outside among the plurality of Y-electrodes to generateelectric beat oscillation in the target region by an absolute value of adifference between the first and second frequencies.
 2. A tactile sensepresentation device, comprising: a supporting substrate; a plurality ofX-electrodes extended in parallel to each other along a first directionon the supporting substrate; a plurality of Y-electrodes extended inparallel to each other along a second direction on the supportingsubstrate by being insulated from the X-electrodes; and a drivingcircuit which applies a first-frequency voltage signal to theX-electrode corresponding to information regarding a target regioninputted from outside among the plurality of X-electrodes, and applies asecond-frequency voltage signal to the Y-electrode corresponding toinformation regarding the target region inputted from outside among theplurality of Y-electrodes, wherein: the first and second frequencies areboth 500 Hz or more; and there is a period where an absolute value of adifference between the first and second frequencies is larger than 10 Hzand less than 1000 Hz.
 3. The tactile sense presentation device asclaimed in claim 2, wherein the driving circuit includes a functionwhich grounds an electrode to which the first-frequency voltage signalis not applied among the plurality of X-electrodes and an electrode towhich the second-frequency voltage signal is not applied among theplurality of Y-electrodes or applies a direct current voltage to suchelectrodes.
 4. The tactile sense presentation device as claimed in claim2, wherein the driving circuit includes a function which applies athird-frequency voltage signal to an electrode to which thefirst-frequency voltage signal is not applied among the plurality ofX-electrodes and to an electrode to which the second-frequency voltagesignal is not applied among the plurality of Y-electrodes.
 5. Thetactile sense presentation device as claimed in claim 4, wherein: thethird frequency is between 2.5 Hz and 5 Hz, both inclusive, or 500 Hz ormore; and an absolute value of a difference between the third frequencyand the first frequency and an absolute value of a difference betweenthe third frequency and the second frequency are both 10 Hz or less or1000 Hz or more.
 6. The tactile sense presentation device as claimed inclaim 2, wherein the driving circuit includes a function which appliesthe first-frequency voltage signal to the X-electrodes corresponding toa first target region while applying the second-frequency voltage signalto the Y-electrodes corresponding to the first target region and, at thesame time, applies a third-frequency voltage signal to the X-electrodescorresponding to a second target region while applying afourth-frequency voltage signal to the Y-electrodes corresponding to thesecond target region.
 7. The tactile sense presentation device asclaimed in claim 6, wherein: the first to fourth frequencies are all 500Hz or more; an absolute value of a difference between the first andsecond frequencies and an absolute value of a difference between thethird and fourth frequencies are both larger than 10 Hz and less than1000 Hz; and an absolute value of a difference between the first andfourth frequencies and an absolute value of a difference between thesecond and third frequencies are both 10 Hz or less or 1000 Hz or more.8. The tactile sense presentation device as claimed in claim 2, whereinin a plurality of prescribed target regions, an absolute value of adifference of the frequencies of voltage signals applied by the drivingcircuit to the X-electrodes and the Y-electrodes contained in the targetregions is larger than 10 Hz and less than 1000 Hz; and in intersectionparts excluding the target regions, which are formed by the X-electrodesor the Y-electrodes constituting the target regions, an absolute valueof a difference in the frequencies of the voltage signals applied to theX-electrodes and the Y-electrodes forming the intersection parts is 10Hz or less or 1000 Hz or more.
 9. The tactile sense presentation deviceas claimed in claim 2, wherein: on a plan view of the supportingsubstrate, the X-electrodes and the Y-electrodes are both formed bycoupling a plurality of rhombic electrodes in a form like a string ofbeads via connection parts; the X-electrodes and the Y-electrodesoverlap with each other in the connection parts; and the rhombic partsof the X-electrodes and the Y-electrodes are neighboring to each other.10. The tactile sense presentation device as claimed in claim 2,wherein: on a plan view of the supporting substrate, the X-electrodesand the Y-electrodes are both formed by coupling a plurality of specificshape electrodes in a form like a string of beads via connection parts,the X-electrodes and the Y-electrodes overlap with each other in theconnection parts, and the specific shape parts of the X-electrodes andthe Y-electrodes are neighboring to each other; and the specific shapepart of the X-electrodes or the Y-electrodes intersects with a firststraight line which connects a first intersection part and a secondintersection part among intersection parts of arbitrary X-electrodes andarbitrary Y-electrodes described above and is not in parallel to thefirst and second directions or a second straight line which connects thefirst intersection part and a third intersection part among intersectionparts of arbitrary X-electrodes and arbitrary Y-electrodes and is not inparallel to the first and second directions.
 11. The tactile sensepresentation device as claimed in claim 9, wherein: on a plan view ofthe supporting substrate, either the X-electrodes or the Y-electrodesare formed by connecting the plurality of electrodes via connectionparts formed integrally with identical material as a material of theplurality of electrodes; and the other ones of the X-electrodes and theY-electrodes include bridge electrodes which electrically connect partswhere the plurality of electrodes are disconnected.
 12. The tactilesense presentation device as claimed in claim 9, wherein: on a plan viewof the supporting substrate, the X-electrodes are formed on a firstsupporting substrate by connecting the plurality of electrodes viaconnection parts formed integrally with identical material as a materialof the plurality of electrodes; the Y-electrodes are formed on a secondsupporting substrate by connecting the plurality of electrodes viaconnection parts formed integrally with identical material as a materialof the plurality of electrodes; and the first and second supportingsubstrates are adhered to each other by sandwiching an insulating film.13. The tactile sense presentation device as claimed in claim 9,wherein: on a plan view of the supporting substrate, the X-electrodesare formed on the supporting substrate by connecting the plurality ofelectrodes via connection parts formed integrally with identicalmaterial as a material of the plurality of electrodes; and theY-electrodes are formed on the supporting substrate by connecting theplurality of electrodes via connection parts formed integrally withidentical material as a material of the plurality of electrodes bysandwiching an insulating film between with the X-electrodes.
 14. Thetactile sense presentation device as claimed in claim 2, wherein theplurality of X-electrodes are disposed in parallel to each other at apitch smaller than 5 mm, the plurality of Y-electrodes are disposed inparallel to each other at a pitch smaller than 5 mm.
 15. The tactilesense presentation device as claimed in claim 2, wherein: the drivingcircuit includes a function which applies the first-frequency voltagesignal of 500 Hz or more to the X-electrodes corresponding toinformation regarding the target region inputted from outside among theplurality of X-electrodes and applies the second-frequency voltagesignal of 500 Hz or more to the Y-electrodes corresponding toinformation regarding the target region among the plurality ofY-electrodes; and changes at least one of the first and secondfrequencies chronologically within a range that is not lower than 500Hz.
 16. The tactile sense presentation device as claimed in claim 15,comprising: a first period where an absolute value of a differencebetween the first frequency and the second frequency is larger than 10Hz and less than 1000 Hz; and a second period where an absolute value ofa difference between the first frequency and the second frequency is 10Hz or less or 1000 Hz or more.
 17. The tactile sense presentation deviceas claimed in claim 16, wherein the first period and the second periodare set alternately.
 18. The tactile sense presentation device asclaimed in claim 15, wherein the driving circuit continuously changes atleast one of the first and second frequencies in a range that is notlower than 500 Hz according to time.
 19. An electronic apparatus,comprising: a touch-panel type display device which displays aprocessing result executed by a processor provided therein and acceptsan operation input which corresponds to the processing result; and thetactile sense presentation device as claimed claim 1, which presents asense of texture corresponding to the display of the processing result.20. A mobile unit, comprising the electronic apparatus as claimed inclaim 19 loaded as an on-vehicle device.
 21. A tactile sensepresentation method used with a tactile sense presentation device whichcomprises: a supporting substrate; a plurality of X-electrodes extendedin parallel to each other along a first direction on the supportingsubstrate; and a plurality of Y-electrodes extended in parallel to eachother along a second direction on the supporting substrate by beinginsulated from the X-electrodes, wherein: a control unit givesinformation regarding a target region inputted from outside to a drivingcircuit; and the driving circuit applies a first-frequency voltagesignal to the X-electrodes corresponding to the target region, andapplies a second-frequency voltage signal to the Y-electrodescorresponding to the target region to generate electric beat oscillationin the target region by an absolute value of a difference between thefirst and second frequencies.